a radioactive substance has a half-life of 2 seconds. A scientist begins with a sample of 20 grams. How much of the substance remains after 8 seconds?
Answer:
1.25 g
Step-by-step explanation:
you start with 20g at 0 seconds.
divide by half after 2 seconds and you have 10g.
at 4 seconds you have 5g.
at 6 seconds you have 2.5g.
at 8 seconds you have 1.25g.
The size of the substance after 8 seconds will be 1.25 g
What is an expression?The mathematical expression combines numerical variables and operations denoted by addition, subtraction, multiplication, and division signs.
Mathematical symbols can be used to represent numbers (constants), variables, operations, functions, brackets, punctuation, and grouping. They can also denote the logical syntax's operation order and other properties.
Given that a radioactive substance has a half-life of 2 seconds. A scientist begins with a sample of 20 grams.
Start with 20g at 0 seconds and divide by half after 2 seconds and you have 10g.
4 seconds you have 5g.
6 seconds you have 2.5g.
8 seconds you have 1.25g.
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which expession represents the product of 3 and 7
3 × 7
i took the test
Directions: Directions: Identify x1, x2, y1, and y2. Solve for the of the line passing through the given points. Identify if the slope is positive, negative, zero, or undefined.
1.(2,1) and (5,3)
2.(-2,1) and (1, -3)
3.(4,1) and (5,1)
4.(7,-1) and (7,5)
5.(-2,1) and (3,6)
Step-by-step explanation:
Number 1
m = (y2 - y1)/(x2 - x1)
m = (3 - 1)/(5 - 2)
m = 2/3 POSITIVE
Number 2
m = (y2 - y1)/(x2 - x1)
m = (-3 - 1)/(1 + 2)
m = -4/3 NEGATIVE
Number 3
m = (y2 - y1)/(x2 - x1)
m = (1 - 1)/(5 - 4)
m = 0/1
m = 0 ZERO
Number 4
m = (y2 - y1)/(x2 - x1)
m = (5 - 1)/(7 - 7)
m = 4/0
m = UNDEFINED
Number 5
m = (y2 - y1)/(x2 - x1)
m = (6 - 1)/(3 + 2)
m = 5/5
m = 1 POSITIVE
write a peacewise function for the graph
please help me
Answer:
[tex]\left \{ {{y=x; \ \ x\le 0} \atop {y=4+ \frac12x;\ \ x>0}} \right.[/tex]
Step-by-step explanation:
If you look at the graph you see that:
before 0, the graph has same y as it has x, or y=x.
after 0, the graph starts at 4, and increases by 1 every 2 steps horizontally, or has a slope of 1/2.
Finally, the 0 has to be included in the blue part of the graph based on where the solid dot is.
can someone help me please
Answer:
#5) Its line “k”
Well to solve this you need to know what negative slopes are.
They decrease from height from left to right
And also a slope is always calculated like this
rise -> run
Think of it like a bed.
You have to wake up which means you have to rise and then you run to do whatever it is you gotta do.
Rise is going vertical and run is going horizontal.
So for line K you have it because since its negative its -3/1 so technically its -3 rise(basically fall since its negative), 1 run (right).
#6) 1/2 is the slope of line N. Or (c)
Well n is a potsive slope so we can automatically remove a and b.
And we can count like this, it started from the orgin it looks like (but you can use any given point really) and then just follow it, rise 1 and run 2. Rise 2 and run 3 doesn’t work so it has to be 1.2 or (c)
Solve for x x^2 + 6x + 1 = 0
Answer:
x = -.1715 ≈ - .172 or x = -5.83
Step-by-step explanation:
x² + 6x + 1 = 0
x² + 6x = -1
Complete the square Add to both sides (1/2 of the x-term, then square it.)
x² + 6x + 9 = -1 + 9
(x + 3)(x + 3) = 8
(x + 3)² = 8
[tex]\sqrt{(x + 3)^{2}[/tex] = [tex]\sqrt{8}[/tex]
x + 3 = ± [tex]\sqrt{8}[/tex]
x = -3 ± [tex]\sqrt{8}[/tex]
x = -3 + [tex]\sqrt{8}[/tex] or x = -3 - [tex]\sqrt{8}[/tex]
x = -.1715 ≈ - .172 or x = -5.83
2x2-5x-2 solve by quadratic formula 9leave answers in simplest radical form)
Answer:
-5x+2
Step-by-step explanation:
1. Multiply number 2 and 2=4 so it is
4-5x-2
2. Combine like terms
-5x+4-2
3. Subtract the numbers
-5x+2
solutions: ( x = 2 & x = -2 )
hmmmmhmmmmmmmmmmmmmmmmmmmmmm
If K = F( A + B ) , find “ A ” if F = 2 , B = 3 , K = 10
Answer:
The value of A is 2
Step-by-step explanation:
F = 2 , B = 3 , K = 10
K = F( A + B )
10 = 2(A + 3)
10 = 2A + 6
Now, Subtract 6 from each side we get,
10 - 6 = 2A + 6 - 6
4 = 2A
2A = 4
Now, divide both side by 2 we get,
2A/2 = 4/2
A = 2
Thus, The value of A is 2
FOR VERIFICATION ONLY :-K = F( A + B )
10 = 2(2 + 3)
10 = 2(5)
10 = 10
L.H.S = R.H.S
Hence Proved!
-TheUnknownScientist 72
You want to have $200,000 when you retire in 25 years. If you can earn 3% interest rate compounded continuously, how much would you need to deposit now into the account to reach your retirement goal?
9514 1404 393
Answer:
$94,473.31
Step-by-step explanation:
The multiplier in 25 years is ...
e^(rt) = e^(0.03·25) = e^0.75 ≈ 2.117
To have an account value of $200,000 in 25 years, you need to deposit now ...
$200,000/2.117 = $94,473.31
_____
When this amount is multiplied by 2.117, the result is 200,000.
Solve for n.
9 =
n
2
+ 7
n =
Answer:
9/n-2=7
We move all terms to the left:
9/n-2-(7)=0
Domain of the equation: n!=0
n∈R
We add all the numbers together, and all the variables
9/n-9=0
We multiply all the terms by the denominator
-9*n+9=0
We add all the numbers together, and all the variables
-9n+9=0
We move all terms containing n to the left, all other terms to the right
-9n=-9
n=-9/-9
n=1
Answer:
n = 1
Step-by-step explanation:
2 x 1 = 2
2 + 7 = 9
help!! !,
is it right or not
Answer:
No
Step-by-step explanation:
The answer is to find the sum of each number, because factors are pulling out from total numbers, but when multiplying you don't need to pull out anything so it would be number
Yep!!! Your correct
Write two Pythagorean triplets each having one of the numbers as 5.
Answer:
3, 4, 5 and 5, 12, 13
Step-by-step explanation:
The square of the largest side is equal to the sum of the squares of the other 2 sides.
5² = 3² + 4²
13² = 5² + 12²
The 2 triplets are (3, 4, 5 ) and (5, 12, 13)
80% of __ is 16 help
Answer:
80% of 20 is 16.
Step-by-step explanation:
Hello darling, the answer is 20 ^^
if a/3=b/2, what are the following ratios?
a+b/b
Answer:
1
a+1
es posible q hayan doble respuesta
Step-by-step explanation:
Pasos
a+b/b
Divide b entre b para obtener 1.
da
d
(a+1)
La derivada de un polinomio es la suma de las derivadas de sus términos. La derivada de cualquier término constante es 0. La derivada de ax
n
es nax
n−1
.
a
1−1
Resta 1 de 1.
a
0
Para cualquier término t excepto 0, t
0
=1.
1
a+b/b
Divide b entre b para obtener 1.
a+1
What is 2x-3y=12 on a graph?
A car is moving at 12 m/s and has a mass of 600 kg. What is the kinetic energy of the car? (Formula: KE = 1/2mv^2) WILL GIVE BRAINLEST
Answer:
The kinetic energy of the car is 43,200 Joules.
Step-by-step explanation:
KE = (1/2)mv^2
KE = (1/2)(600 kg)(12 m/s)^2
KE = (1/2)(600 kg)(144 m^2/s^2)
KE = 43,200 kg*m^2/s^2 = 43,200 Joules
Answer:
Step-by-step explanation:
KE= 1/2mv^2
KE = 1/2(600) 12^2
KE = 300 * 144 = 43200J
the perimeter of this triangle is 46cm find x
Answer:
the value of x is 12
......
9. 2 less than 3 times a number is the same as 2114. What is the number?
Enter your answer as a decimal or simplified mixed number in the box. The number is.
Answer:
705.3 repeated I don't know if that's what you want but
3 times of 705.33 and 2 subtracted is equal to 2114.
What is Simplification?Simplification in mathematical terms is a process to convert a long mathematical expression in simple and easy form.
Given that,
2 less than 3 times a number equal to 2114.
Let the required number is x.
According to given condition,
3x - 2 = 2114
3x = 2114 + 2
3x = 2116
x = 2116 / 3
x = 705.33
The required number is 705.33.
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w + 12 = 20 *
ANSWER ASAP PLS
Answer:
the nwser is 8 please mark brainliest
Step-by-step explanation:
The Sydney Harbour Bridge is approximately 1200 metres long. A model of the bridge is built with a scale of 1:6000. What is the length of the model?
Pick one:
5cm
20cm
200cm
720cm
Answer:
20cmStep-by-step explanation:
The Sydney Harbour Bridge is approximately 1200 metres long. A model of the bridge is built with a scale of 1:6000. What is the length of the model?
Pick one:
5cm
20cm
200cm
720cm
--------------------
scale = 1:6000
so
1200 : 6000 = 0.2m
0.2m = 20 cm
Answer:
20cm
Step-by-step explanation:
«A scale of 1:6000» means the model is smaller than the bridge by a factor of 6000. We can also make up a proportion [tex]\dfrac{1}{6000}=\dfrac{x}{1200}[/tex], where the left side is the scale, x is the model length, 1200 is the bridge length (in meters). So, finding x or just dividing 1200 by 6000, we get 0.2 meters. Provided 1 m = 100 cm, 0.2 m is 0.2 × 100 = 20 cm.
If we convert 0.14 x10^3 to scientific notation, which direction should the
decimal move and how spaces should it move?
Answer:
Move it to the right by 3 spaces.
Step-by-step explanation:
10^3 is 1000
On a number line the negative numbers are on the left and the positive numbers are on the right. So since the exponent is a positive 3 we move it to the right by 3 spaces to get 140
Which best describes the error in finding the area of the parallelogram?
15 meters was used for the height instead of 13 meters.
15 meters was used for the height instead of 13 meters.
8 meters was used for the height instead of 13 meters.
8 meters was used for the height instead of 13 meters.
The product of 8 and 15 is not 120.
The product of 8 and 15 is not 120.
The formula to use should have been A=12bh instead of A=bh.
The formula to use should have been, cap A is equal to 1 half b h instead of cap A is equal to b h.
Question 2
Correct the error.
A=
=
m2
Answer:
104
Step-by-step explanation:
HELP GIVING BRAINLIEST (NO LINKS) 50 POINTS
Expression A: 2(x + 1)
Expression B: 2x + 2
which statement does not show that these expressions are equivalent
A.subsitiuting any value of x makes the expressions equivalent
B. Both expressions involve addition
C. The expressions name the same number regardless of the value of x
D. 2(x +1) can be rewritten as 2x + 2 using the distributive property
solve pls brainliest
Answer:
64%
Step-by-step explanation:
Step 1: Divide 16 by 25
-> [tex]\frac{16}{25}[/tex] -> [tex]0.64[/tex]Step 2: Multiply quotient by 100.
[tex]0.64 * 100[/tex] [tex]6.4 * 10[/tex] [tex]64[/tex] 64%Therefore, 16/25 as a percentage is 64%.
Answer:
Well you can make a proportion
Percentage means ”Out of a hundred”
So you can make a proportion with any fraction Equal to x/100 since
X is the unknown perctange.
in this case it’s 16/25
16/25 = x/100
So cross multiply To solve for X
1600= 25x
x= 64
So 64 Percent
In this case you can use benchmarks. If you do it more or long enough, you’d memorize them.
In this case 25 is a bench mark of 1/4 or 25. 25 goes into 100 4 times so you can multiply 16 by 4 to get your percentage since if you do multiply 4, you have to do it to both the numerator and the Denominator.
so 16/25
16*4= 64
25*4=100
64/100 or 64 percent.
Common benchmarks for percentages
5, 10, 20, 25, 50
5 is always multiply by 20
10 is always multiply by 10
20 is always multiplied by 5
25 is always multiplied by 4
50 is always multiplied by 2
PLEASE HELP ASAP GIVING BRAINLIEST
Answer:
brainliest mo munako
Step-by-step explanation:
bago answer pede maliwaag ba
What is the diameter of a circular swimming pool with the radius of 8 feet
help me please asap
Answer:
5/6
Step-by-step explanation:
2/
3
: 4/
5
= 2/
3
· 5/
4
= 2 · 5/
3 · 4
= 10/
12
= 2 · 5/
2 · 6
= 5/
6
HELPPP OMGGG
10, 10, 18, 18, 10, 5, 12, 13
Find the median and mean number of hours for these students.
If necessary, round your answers to the nearest tenth.
-2x -3 for x = -3
( Evaluate the following algebraic expression )
Answer:
well its -2*-3-3 so
-2*-3 is 6-3 is 3
Step-by-step explanation:
