A tumor is injected with 0.3 grams of Iodine-125, which has a decay rate of 1.15% per day. To the nearest day, how long will it take for half of the Iodine-125 to decay?
Answer:
The time required is 60.3 days.
Step-by-step explanation:
initial amount, No = 0.3 g
rate, r = 1.15 % per day = 0.0115 per day
final amount, N = 0.15 g
Let the time is t.
[tex]N = No e^{-rt}\\\\0.15 = 0.3 e^{-0.0115 t}\\\\0.5 =e^{-0.0115 t}\\\\- 0.6931 = - 0.0115 t \\\\t = 60.3 days[/tex]
Question 1 of 10
If f(x)= 2 -3 and g(x) = 4x2 + x - 4, find (f+ g)(x).
O A. 4x+x-7
O B. 4x2 +5x-1
O c. 6x2 - 7
OD 6+x-1
A
SUBMIT
Answer:
I believe it's A
Step-by-step explanation:
I'm not sure sorry if its wrong
Zelina scored 10% higher on her second quiz than on her first quiz. On her third quiz, Zelina scored 20% higher than on her second quiz. Her third quiz score is what percent higher than her first quiz score?
Answer:
30%
Step-by-step explanation:
you just add 10% and 20%
Hope it helps c:
Zelina scored 32% higher on the third quiz than on her first quiz.
What is the percentage?The Percentage is defined as representing any number with respect to 100. It is denoted by the sign %.
Given that:-
Zelina scored 10% higher on her second quiz than on her first quiz. On her third quiz, Zelina scored 20% higher than on her second quiz.From the given data we will see that:-
1 ) Zelina scored 10% higher on her second quiz than on her first quiz.
SQ = 1.10 FQ
2 ) On her third quiz, Zelina scored 20% higher than on her second quiz
TQ = 1.20SQ
From the above to expression solve for the first quiz:-
TQ = 1.20 x 1.10 FQ
TQ = 1.32FQ
Therefore Zelina scored 32% higher on the third quiz than on her first quiz.
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The graph of a quadratic function has x-intercepts of -7 and -1, and passes through the point (-4,36). Determine the equation of the quadratic function in the form
f(x) = a(x - m)(x − n).
9514 1404 393
Answer:
f(x) = -4(x +7)(x +1)
Step-by-step explanation:
The x-intercepts tell us that m=-7 and n=-1. We can use the given point to find 'a'.
f(-4) = 36
a(-4+7)(-4+1) = 36
a = 36/-9 = -4 . . . . divide by the coefficient of 'a'
Filling in the known values, ...
f(x) = -4(x +7)(x +1)
Let log base aU=X and log base aV=Y, then a to the x power =? and a to y power =?
Answer:
[tex]{ \bf{ log_{a}(U) = x}} \\ { \boxed{ \tt{ {a}^{x} = U}}} \\ \\ { \bf{ log_{a}(V) = y}} \\ { \boxed{ \tt{ {a}^{y} = V }}}[/tex]
Solve the system using substitution. x+y=-2 and x-y=-8
Answer:
1) x+y=-2
x=-2-y
2) x-y=-8
substitude value of x
(-2-y)-y=-8
-2-2y=-8
-2y=-6
y=3
Substitute value of y in 1
x=-2-3
x=-5
Brainliest please~
The numbers of home runs that Barry Bonds hit in the first 18 years of his major league baseball career are listed below. Find the mean and median number of home runs. Round the mean to the nearest whole number. Which measure of central tendency- the mean or the median- best represents the data? Explain your reasoning.
16 25 24 19 33 25 34 46 37
33 42 40 37 34 49 73 46 45
Answer:
Mean = 35.56
Median = 35.5
Step-by-step explanation:
Given the data:
16 25 24 19 33 25 34 46 37
33 42 40 37 34 49 73 46 45
Reordered data :
16, 19, 24, 25, 25, 33, 33, 34, 34, 37, 37, 40, 42, 45, 46, 46, 49, 73
The mean = ΣX / n
n = sample size ; ΣX = sum of values
The mean = 658 / 18
The mean = 36.56
The Median = 1/2(n+1)th term
1/2(18+1)th term = 1/2(19)th term = 9.5 term
Median = (9th + 10th) / 2 = (34 + 37) / 2 = 35.5
A sample of 34 observations is selected from a normal population. The sample mean is 15, and the population standard deviation is 3. Conduct the following test of hypothesis using the 0.10 significance level. H0: μ ≤ 14 H1: μ > 14
Required:
a. Compute the value of the test statistic.
b. What is the p-value?
Answer:
1.944 ;
0.026
Step-by-step explanation:
Given :
Sample size, n = 34
Sample mean, xbar = 15
Population standard deviation, σ = 3
The hypothesis :
H0: μ ≤ 14
H1: μ > 14
The test statistic :
Test statistic = (xbar - μ) ÷ (σ/√(n))
Test statistic = (15 - 14) ÷ (3/√(34))
Test statistic = 1 / 0.5144957
Test statistic, Z = 1.944
The Pvalue :
Using the Pvalue from test statistic value :
Pvalue(1.944) = 0.026
Pvalue < α ; Reject H0
Couldn’t figure this out help please
(B)
Step-by-step explanation:
Rewrite the equations into their standard forms. The first one can be rewritten as
[tex]10x - 12y = -5[/tex]
and the 2nd can be rewritten as
[tex]3x + 5y = -1[/tex]
Solving this system either by substitution or elimination, we get
[tex]x = -\dfrac{37}{86}\:\:\text{and}\:\:y= \dfrac{25}{86}[/tex]
If you add x + y, you'll get a negative number.
9514 1404 393
Answer:
B. x + y < 0
Step-by-step explanation:
The two equations can be cleared of fractions by multiplying by 15.
15(2/3(x +1) -4/5y) = 15(1/3)
10(x +1) -12y = 5
10x -12y = -5
and
15(2/5x +1/3(2y +1)) = 15(1/5)
6x +5(2y +1) = 3
6x +10y = -2
3x +5y = -1 . . . . . eliminate common factor of 2
__
You can find the solutions any way you like, but you can answer the question without doing that. The lines are not parallel, nor coincident, so there is exactly one solution. (choices C and D are incorrect)
If we can locate the solution relative to the line x + y = 0, we can tell if choice A or choice B is correct. A quick look at the intercepts of the equations tells us the solution cannot lie in quadrants 1 or 4. The negative y-intercept and shallow slope (-3/5) of the second equation tells us the solution must lie below the line x + y = 0. That means x+y < 0, choice B.
_____
In the attached graph, the line x+y=0 is dashed orange. Above that line, x+y>0; below that line, x+y<0. We see the intersection point of the red and blue lines is in the region where x+y < 0.
For standard form equation ax+by = c, the x- and y-intercepts are c/a and c/b, respectively, so are easy to find from that form. Knowing these makes it easy to make a sketch of the graph, locating the solution point relative to the line x+y = 0.
Translate the following sentence into an algebraic inequality:
The difference of twice a number, x, and eleven is, at most, the sum of twenty and a number, x.
Question 4 options:
A)
2x∕11 ≥ 20 – x
B)
9x ≥ 20 + x
C)
2x + 11 ≥ 20x
D)
2x – 11 ≤ 20 + x
Answer:
it have to be letter c
Step-by-step explanation:
this the only problem matches with the question
The inequality represent the given phrase is 2x-11≤20+x. Therefore, option D is the correct answer.
What are inequalities?Inequalities are the mathematical expressions in which both sides are not equal. In inequality, unlike in equations, we compare two values. The equal sign in between is replaced by less than (or less than or equal to), greater than (or greater than or equal to), or not equal to sign.
Given that, the difference of twice a number, x, and eleven is, at most, the sum of twenty and a number, x.
The difference of twice a number, x, and eleven is
2x-11
The sum of twenty and a number, x
20+x
So, inequality is 2x-11≤20+x
The inequality represent the given phrase is 2x-11≤20+x. Therefore, option D is the correct answer.
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The length of a rectangle is 2 cm longer than its width.
If the perimeter of the rectangle is 36 cm, find its area.
Answer:
80 cm^2
Step-by-step explanation:
Let the width of the rectangle equal x. This means the length is x + 2, as it is 2 cm longer than the width. The formula for perimeter is: P = 2l + 2w, and substitute in the values of the length, width, and perimeter:
P = 2l + 2w
36 = 2(x + 2) + 2(x)
36 = 2x + 4 + 2x
36 = 4x + 4
4x = 32
x = 8
x represents the width, so the width is 8 and the length is 10. Area is length times width, so the area is 8 x 10 or 80 cm^2.
Step-by-step explanation:
let x be the width
p=2l+2w
36=2(2)+2(x)
36=4+2x
36-4=2x
32/2=2x/2(simplify)
x=16
therefore the width is 16cm
area of the rectangle is l×w
=2×16
=32cm"
therefore the area is 32cm"
The lengths of the three sides of a triangle are 17, 18, and 19. Classify it as acute, obtuse, or right.
Answer:
acute
Step-by-step explanation:
That triangle is an obtuse triangle
An English professor assigns letter grades on a test according to the following scheme. A: Top 13% of scores B: Scores below the top 13% and above the bottom 55% C: Scores below the top 45% and above the bottom 20% D: Scores below the top 80% and above the bottom 9% F: Bottom 9% of scores Scores on the test are normally distributed with a mean of 78.8 and a standard deviation of 9.8. Find the numerical limits for a C grade. Round your answers to the nearest whole number, if necessary.
Answer:
Scores between 71 and 80 give a C grade.
Step-by-step explanation:
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Scores on the test are normally distributed with a mean of 78.8 and a standard deviation of 9.8.
This means that [tex]\mu = 78.8, \sigma = 9.8[/tex]
Find the numerical limits for a C grade.
Above the bottom 20%(20th percentile) and below the top 45%(below the 100 - 45 = 55th percentile).
20th percentile:
X when Z has a p-value of 0.2, so X when Z = -0.84.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]-0.84 = \frac{X - 78.8}{9.8}[/tex]
[tex]X - 78.8 = -0.84*9.8[/tex]
[tex]X = 70.57[/tex]
So it rounds to 71.
55th percentile:
X when Z has a p-value of 0.55, so X when Z = 0.125.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]0.125 = \frac{X - 78.8}{9.8}[/tex]
[tex]X - 78.8 = 0.125*9.8[/tex]
[tex]X = 80[/tex]
Scores between 71 and 80 give a C grade.
There is a rack of 15 billiard balls. Balls numbered 1 through 8 are solid-colored. Balsa numbered 9 through 15 contain stripes. If one ball is selected at random, determine the odds for it being striped.
If one ball is selected at random, the odds for it being striped are 7 out of 15, or 7/15.
What do we know?
We know that there are 15 billiard balls.
We also know that balls numbered 1 through 8 are solid-colored, so we have 8 solid-colored balls.
And the other 7 balls are striped.
Now we want to find the probability for a randomly selected ball to be a striped ball.
Because all the balls have the same probability of being randomly selected, the probability of randomly selecting a striped ball is equal to the quotient between the number of striped balls (7) and the total number of balls (15).
Then we have:
P = 7/15 = 0.467
That quotient is also what is called the "odds"
So if one ball is selected at random, the odds for it being striped are 7 out of 15, or 7/15.
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find the lateral surface area of this cylinder. round to the nearest tenth. r=5cm 5cm LSA (in the image)
Answer:
157 cm²
Step-by-step explanation:
A cylinder is given to us and we need to find out the lateral surface area of the cylinder . We can see that the ,
Height = 5cm
Radius = 5cm
We know that we can find the lateral surface area of the cylinder as ,
[tex]\rm\implies LSA_{cylinder}= 2\pi r h [/tex]
Substitute upon the respective values ,
[tex]\rm\implies LSA = 2 \times 3.14 \times 5cm \times 5cm [/tex]
Multiply the numbers ,
[tex]\rm\implies \boxed{\blue{\rm LSA = 157 \ cm^2 }}[/tex]
Hence the Lateral surface area of the cylinder is 157 cm² .
[tex] \setlength{\unitlength}{1mm}\begin{picture}(5,5)\thicklines\multiput(-0.5,-1)(26,0){2}{\line(0,1){40}}\multiput(12.5,-1)(0,3.2){13}{\line(0,1){1.6}}\multiput(12.5,-1)(0,40){2}{\multiput(0,0)(2,0){7}{\line(1,0){1}}}\multiput(0,0)(0,40){2}{\qbezier(1,0)(12,3)(24,0)\qbezier(1,0)(-2,-1)(1,-2)\qbezier(24,0)(27,-1)(24,-2)\qbezier(1,-2)(12,-5)(24,-2)}\multiput(18,2)(0,32){2}{\sf{5cm}}\put(9,17.5){\sf{5cm}}\end{picture}[/tex]
Answer:
314.2 is the Surface area
Step-by-step explanation:
Hope it Helps! If you have any questions, feel free to comment! :)
2π(5)(5)+2π(5^2)
2π(25)+2[tex]\pi[/tex](25)
50π+50π=100π
314.2 is the answer. That's what we get after rounding up! :)
Which best describes the relationship between the line that passes through the points (6, –1) and (11, 2) and the line that passes through the points (5, –7) and (8, –2)?
A. same line
B. neither perpendicular nor parallel
C. perpendicular
D. parallel
Answer:
Step-by-step explanation:
slope of line through (6,-1) and (11,2) = (-1 - 2)/(6 - 11) = 3/5
slope of line through (5,-7) and (8,-2) = (-7 - (-2))/(8 - 5) = -5/3
product of the slopes = -1, so the lines are perpendicular.
If\[\displaystyle\frac{\sqrt{600} + \sqrt{150} + 4\sqrt{54}}{6\sqrt{32} - 3\sqrt{50} - \sqrt{72}} = a\sqrt{b},\]where $a$ and $b$ are integers and $b$ is as small as possible, find $a+b.$
9514 1404 393
Answer:
12
Step-by-step explanation:
Apparently, you want the sum a+b when ...
[tex]\[\displaystyle\frac{\sqrt{600} + \sqrt{150} + 4\sqrt{54}}{6\sqrt{32} - 3\sqrt{50} - \sqrt{72}} = a\sqrt{b},\][/tex]
A calculator can show you the expression on the left evaluates to √243. In simplest terms, that is 9√3, so we have a=9, b=3 and ...
a+b = 9+3 = 12
Answer:
12
Step-by-step explanation:
Anne is building bookcases that are 3.1 feet long. How many complete shelves can be cut from a 12-foot board?
Answer: 3 shelves
Step-by-step explanation:
12 ÷ 3.1 = 3.87…
Since this is more than 3 but less than 4, we can build 3 full shelves with a leftover.
It costs $7.45 for 2.5 pounds of round steak. What is the unit rate?
A.$9.95 per pound
B.$18.63 per pound
C.$2.50 per pound
D.$2.98 per pound
Answer:
D.
Step-by-step explanation:
Since the unit rate is in dollars per pound, we divide the cost (in dollars) by the weight (in pounds.)
($7.45)/(2.5 lb) = $2.98 per pound
Answer: D.
1/2 sin x sin (2x) + Cos 3 x
Answer:
1.047734151
Step-by-step explanation:
Type into calculator
1/2sin(2x)+cos(3x)
Compute how many 7-digit numbers can be made from the digits 1, 2, 3, 4, 5, 6, 7 if there is no repetition and the odd digits must appear in an unbroken sequence. (Examples: 3571264 or 2413576 or 2467531, etc., but not 7234615.)
Answer:
Number of 7-digit numbers that can be made from the digit is 576
Step-by-step explanation:
Given the data in the question;
digits ⇒ 1, 2, 3, 4, 5, 6, 7
Number of odd numbers in the given digits = 4
Number of even numbers in the given digits = 3
now, we take the odd digits as a single unit.
so, number of ways the odd digits can be arranged with the unit will be 4!.
Now, lets consider the unit of 4 odd digits with 3 even digits.
there are 4 units.
so the number of possible arrangements of these 4 units = 4!
hence, Number of 7-digit numbers that can be made from the digits will be;
⇒ Number of possible arrangements of 4 units × Number of ways in which the odd digits can be arranged within the unit.
⇒ 4! × 4!
⇒ 576
Therefore, Number of 7-digit numbers that can be made from the digit is 576
Tìm x không âm biết √x =3
Answer:
x=9
Step-by-step explanation:
[tex]\sqrt{x}[/tex]=3
[tex]\sqrt{x}[/tex]^2=3^2
x=9
find the value of X in each figure below
Answer:
168). C
169). C
170). C
Step-by-step explanation:
For the first angle, it is a right angle, so it measures 90 degrees.
x and 50 are complementary angles, meaning they add up to 90 degrees.
So, subtract 50 from 90 to get 40, which is equal to x.
45 and x are supplementary angles, meaning they add up to 180 degrees.
Subtract 45 from 180 to get 35 degrees, which is the measure of angle x.
All angles in a triangle add up to 180 degrees.
So, 70 + 56 = 126, 180 - 126 = 54.
Since the unknown angle is x - 5, 54 + 5 = 59, which the the measure of angle x - 5.
In the picture below, which lines are lines of symmetry for the figure?
A. 1 and 3
B. only 3
C. 2
D. 1, 2, and 3
A line of symmetry would separate a shape to make multiple shapes that are exactly the same.
The answer is C.2
classmate Date 8) Solve the word problems a) If 576 balls are arranged in equal number of rows and columns, find the numbers of rows.
Answer:
24
Step-by-step explanation:
The number of rows (x) should b equal to the number of columns (x).
x²=576
x=√576 taking the square root of the product
x=24
Marilyn is retiring and wants to set up a 25-year annuity with 140 000 of her savings . The annuity earns 7.7 compounded monthly How much will Marilyn receive every month ?
Answer:
marilyn isrestiring and wants to set up a 25-year annuity earns 7.
Since lim n→ infinity (.............) = ...........
Notice that
[tex]\dfrac{4n+1}{8n+2}=\dfrac{4n+1}{2(4n+1)}=\dfrac12[/tex]
So by the root test,
[tex]\displaystyle\lim_{n\to\infty}\sqrt[n]{\left|\left(\frac12\right)^{2n}\right|} = \frac14 < 1[/tex]
and so the series converges (absolutely).
What is 5% of 483759????
Step-by-step explanation:
5% of 483759 is 24187.95
Answer: The answer is 24,187.95
Step-by-step explanation:
483759 Multiplied by 0.05 = 24,187.95
If my saving x$ grows 10% every year how much will I have in:
1 year
2 year
5 year
Answer:
[tex]1.1x, 1.21x, 1.61051x[/tex]
Step-by-step explanation:
If you saving grows [tex]10 \%[/tex] every year, then your saving is [tex]1.1\\[/tex] times your saving from last year. Therefore, after one year, you will have [tex]1.1x\\[/tex], then after [tex]2[/tex] years, you will have [tex](1.1)^2 \cdot x=1.21x[/tex], then after [tex]5[/tex] years, you will have [tex](1.1)^5 \cdot x = 1.61051x[/tex].
Answer:
$1.1x, $1.21x, $1.61x
Step-by-step explanation:
The Science Club arranged a trip to Smithsonian. Only 2/3 of the members were able to attend, which left one seat empty on the 25-passenger bus. How many members does the Science Club have?
Answer:
36 members
Step-by-step explanation:
Let x = the number of science club members
There are 24 people on the bus (1 seat empty on the 25 seat bus)
2/3 of the club attended and that equals 24 people on the bus
2/3x = 24
Multiply each side by 3/2
3/2 * 2/3x = 24 * 3/2
x = 36
