Answer:
The sum of the first 20 terms is -1440.
Step-by-step explanation:
We want to find the sum of the first 20 terms of the arithmetic sequence:
4, -4, -12, -20...
The sum of an arithmetic sequence is given by:
[tex]\displaystyle S=\frac{k}{2}(a+x_k)[/tex]
Where k is the number of terms, a is the initial term, and x_k is the last term.
Since we want to find the sum of the first 20 terms, k = 20.
Our initial term a is 4.
Our last term is also the 20th term as we want the sum of the first 20 terms.
To find the 20th term, we can write an explicit formula for our sequence. The explicit formula for an arithmetic sequence is given by:
[tex]x_n=a+d(n-1)[/tex]
Where a is the initial term, d is the common difference, and n is the nth term.
Our initial term is 4. From the sequence, we can see that our common difference is -8 since each subsequent term is eight less than the previous term. Therefore:
[tex]x_n=4-8(n-1)[/tex]
Then the last or 20th term is:
[tex]x_{20}=4-8(20-1)=4-8(19)=-148[/tex]
Therefore, the sum of the first 20 terms are:
[tex]\displaystyle\begin{aligned} S_{20}&=\frac{(20)}{2}\left((4)+(-148))\\&=10(-144) \\&= -1440\end{aligned}[/tex]
Answer:
- 1440
Step-by-step explanation:
First-term is 4 and we subtract 8 to get the next term so the general term is
a(n) = 4 - 8(n -1)
The sum of the sequence is the average of the first and last terms multiplied by the number of terms: (a1 + an)/2 * n
We need the 20th term: a20 = 4 - 8(20–1) = 12 - 160 = - 148
The sum is (4 - 148)/2 * 20 = 10*(-144) = - 1440
help me solve the simultaneous linear inequalities
Answer:
The inequality form is -4<x<-2
The Interval Notation is (-4, -2]
I hope this helps!
Suppose a triangle has sides a, b, and c, and that a2 + b2 > c2. Let 0/ be the
measure of the angle opposite the side of length c. Which of the following
must be true? Check all that apply.
A. 0/ is an acute angle.
B. cos 0/ > 0
C. The triangle is a right triangle.
D. The triangle is not a right triangle.
Hello,
Answer A
Indeed:
[tex]c^2=c^2+b^2-2ab*cos(\theta) < a^2+b^2\\\\-cos(\theta)<0\\\\cos(\theta)>0\ \Longrightarrow \theta < 90^o[/tex]
True statements are:
A. [tex]\theta[/tex] is an acute angle.
C. The triangle is a right triangle.
D. The triangle is not a right triangle.
What is angle?An angle is a combination of two rays (half-lines) with a common endpoint.
Given:
a² + b² > c²
as, the triangle with sides a, b and c.
If this is a right triangle, then the condition a² + b² > c² apply.
Using cosine law.
angle> 90 degrees which is an obtuse angle.
Also, cos [tex]\theta[/tex] is negative.
Hence, the conditions that are true are A, C and D.
Learn more about this concept here:
https://brainly.com/question/1619127
#SPJ2
Someone help me please?
Answer:
([tex]a^{2}[/tex] + 9 ) × (2[tex]a^{2}[/tex] + 1)
for the first one try two but im not sure
The arrow on the spinner will be spun one more time. Based on these results, what is the probability that the arrow will land on the purple section?
In a paragraph, explain what the domain and range is for the function, and how you found your answer: f(x) = x2 + 6x - 25.
Answer:
Domain(-infinity,+infinity)
Range=f(x) >or= - 34
Step-by-step explanation:
Domain for every parabola the domain is (-infinity, +infinity) unless there are any restrictions
Range we look at the y value of the maximum point or minimum points
We find it by finding the turning point
F'(x) =2x+6
0=2x+6
-6=2x
x=-3
F(-3)=(-3)^2+6(-3)-23
=-34
So all value that exist on the f(x) must be greater or =-34
given that O is the center of the circle, find the measure of angle BAC of arc DC = 120
Answer:
30 degrees.
Step-by-step explanation:
DC is given as 120, so start off by finding arc BC.
180-120= Semicircle-DC=60.
BC=60.
Inscribed angles are half of their arcs.
60/2=30.
guys help me
what is the answer?
Step-by-step explanation:
C. represent the number line for x
where x ix
3x>6x> 6/3x>2hope it helps.stay safe healthy and happy.The price of a laptop was first increased by 10% and then the new price was decreased by 20%. The final price was what percent of the initial price.
Answer:
88%
Step-by-step explanation:
to initial price (100%) was increased by 10% (resulting in 110% of the initial price).
then these 110% were decreased by 20%.
so, the final price is actually 80% of 110% of the initial price
20/100 = 1/5
80/100 = 4/5
so, the customer pays only 4/5 of the 110% price.
110 × 4/5 = 22 × 4 = 88%
so, the final price was 88% of the initial price
2.
What is the difference between the lower quartile rainfall of Florida and the lower quartile rainfall of Pennsylvania?
Answer:
0.5 inches
Step-by-step explanation:
The lower quartile is the value on the left side of the box plot
lower quartile for Florida = 3.5 inches
lower quartile for Pennsylvania = 3 inches
difference = 3.5 - 3 = 0.5 inches
The diagram shows a prism …,
Answer:
See figure below.
Step-by-step explanation:
See the figure below.
Convert 10,000 seconds into the number of equivalent hours, minutes, and seconds.
Answer:
She's "Hot"!
Step-by-step explanation:
Look at the diagram. Which angle is supplementary to 1.) 2.) 3.) 4.)
Answer:
it's going to be EOC
Step-by-step explanation:
I used my brain
what is this please help
Answer: The answer in the blank is 2/5.
Step-by-step explanation: To divide fractions, flip the second fraction's denominator and nominator and then change the sign to a multiplication sign. Multiply. 4/5 x 3/1 = 12/5. Make 12/5 a mixed number. Since 12 can hold 2 fives, the people who created this question placed a 2 before the blank. 2/5 is remaining, so the blank is 2/5.
Find RS.
A. 12
B. 5
C. 9
it may be 12...........
Answer:
B) RS=5
Step-by-step explanation:
(2x-6)+(1)+(x-4)=18
2x-6+1+x-4=18
3x-9=18
3x=18+9
3x=27
x=9
Find RS
x-4
9-4
=5
The perimeter of the rectangle below is 46 units. Find the length of side AB.
Write your answer without variables.
D
3x - 2
AB = 0
х
$
?
A
2x
B
Ax
B
Step-by-step explanation:
.....
...
..
A roller coaster starts at point A. It goes up 20 feet, down 32 feet, and then up 16 feet to point B. Write an addition sentence to find the height at point B in relation in point A.
Heklp po pasahan na bukas
Answer:
20+(-32)+16
Step-by-step explanation:
It goes up which is positive then goes down which is negative then goes back up which is positive
Which of these is the equation of the new function?
Answer:
B: g(x) = -4(x + 3)^2
Step-by-step explanation:
When we shift to the left by a units
we have the new equation become
( x + 3)^2
Stretching by a factor of 4, we have it that;
4(x + 3)^2
reflecting over the x-axis means the y-axis value becomes negative
So we have
g(x) = -4(x + 3)^2
Three text messages cost 5 cents to send. how much do 150 cost?
Answer:
30 ,,,,,,,, I hope it's helpful for you
3 text messages = 5 cents
So,
1 text messages
= 5 cents/3
= 5/3 cents
So,
150 text messages
= 150 × (5/3 cents)
= 50 × 5 cents
= 250 cents
When a constant force acts upon an object, the acceleration of the object varies inversely with its mass. When a certain constant force acts upon an object with
mass 7 kg, the acceleration of the object is 4 m/s?. If the same force acts upon another object whose mass is 2 kg, what is this object's acceleration?
Answer:
14 m/s²
Step-by-step explanation:
From the question
a ∝ F/m.............. Equation 1
Where a = aceleration, m = mass, F = force
make F the subject of the equation
F = ma............ equation 2
Given: m = 7 kg, a = 4 m/s²
Therefore,
F = 7(4)
F = 28 N
For another object whose mass is 2 kg,
Make a the subject of equation 2
a = F/m
a = 28/2
a = 14 m/s²
someone help me with my algebra homework please
Answer:
(8,2.40)
Step-by-step explanation:
The Jacksons have a scaled down model of a football field on their property. The measurements of an actual sized field
are shown below.
50 yds
120 yds
The length of the field in the backyard is 30 yards. What is the width?
18.75 yards
6.25 yards
25 yards
12.5 yards
Answer:
Scale model width = 12.5 yards
Step-by-step explanation:
Given:
Actual length of field = 120 yards
Actual width of field = 50 yards
Scale model length = 30 yards
FInd:
Scale model width
Computation:
Scale model width = [Scale model length / Actual length of field] Actual width of field
Scale model width = [30/120]50
Scale model width = [1/4]50
Scale model width = 0.25 x 50
Scale model width = 12.5 yards
Which length is equivalent to 12 yards?
4 feet
9 feet
15 feet
36 feet
Answer:
4 feet
Step-by-step explanation:
1 yard is 3 feet
then 12 yards is 4 feet
Answer:
It is 36.
Step-by-step explanation:
It's simple math
5^4x+3 ×100^-2x+1=50000
Answer:
5^4x+3 ×100^-2x+1=50000
5^4x×100^-2x=49996
isolate the variable by dividing each side by factors that don't contain the variable. Exact Form: x = 8 √ 12499 , Decimal Form: x = 894.39141319 …
Write a function rule for the table.
Answer:
A
Step-by-step explanation:
slope=(1-0)/(5-4)=1
eq. of line through (4,0) with slope 1 is
y-0=1(x-4)
put y=f(x)
f(x)=x-4
Please help due incredibly soon!!!!
Answer:
The surface area is 116.
Step-by-step explanation:
yall rockin w yung kayo
Answer:
YALLLLLLLLL
Step-by-step explanation:heheh okie thats funnie
Convert the following 4.5 hours Into Second- ( Soin 24
Answer: 16,200 Seconds
Step-by-step explanation:
Data: 4.5 hours(h)=x seconds(s)
Step One, Convert Hours Into Minutes
4.5h=4h and 30 minutes(m)
1h=60mx4=240m+30=270m
Reason: Since to convert to seconds, minutes are needed, you have to convert everything to minutes. And with 60 minutes in an hour you have to multiply 60 by 4 to get 240 and add 30 minutes to it(since it's 4.5 hours) to find ourselves at 270 minutes.
Step two, Convert Minutes Into Seconds
1m=60s
270mx60=16,200s
Reason: Since we are ultimately trying to get 4.5 hours into seconds, we have to convert the minutes we have into seconds by multiplying 270 minutes by 60(since 60 seconds are in a minute) to get our final answer of 16,200 seconds.
I hope this helps!
Just Question B!
One of the numbers in the diagram is chosen at random, find the probability that the number is in set B, giving your answer as a decimal.
Gibing brainlist!
Answer:
0.4 or 0.40
Step-by-step explanation:
There are 10 total numbers. 4 of them are in set B.
So, 4/10 are in set B.
The probability is 0.4 because 4 divided by 10 is 0.4.
What is the nth term rule of the quadratic sequence below?
8,14,22,32 ,44, 58, 74...
Answer:
y=n^2+3n+4
Step-by-step explanation:
Sequence,S: 8,14,22,32 ,44, 58, 74...
First differences of S: 6,8,10,12,14,16,...
Second differences of S: 2,2,2,2,2,2,....
It is indeed a quadratic since the 1st differences that are the same are the second differences.
So the 1st term is 8. If the 0th term was listes it would be 4 since 8-4=4 and 6-4=2.
This means our quadratic it is in the form
y=an^2+bn+c where c=4.
So we have y=an^2+bn+4.
Now we can find a and b using two points from our sequence to form a system of equations to solve.
(1,8) gives us 8=a(1)^2+b(1)+4
Simplifying gives 8=a+b+4
Subtracting 4 on both sides gives: 4=a+b
(2,14) gives us 14=a(2)^2+b(2)+4
Simplifying gives 14=4a+2b+4
Subtracting 4 on both sides gives 10=4a+2b
So we have the following system to solve:
4=a+b
10=4a+2b
I'm going to solve using elimination/linear combination style.
Dividing second equation by 2 gives the system as:
4=a+b
5=2a+b
Subtract the 2nd equation from the first gives:
-1=-1a
This implies a=1 since -1=-1(1) is true.
If a+b=4 and a=1, then b=3. Because 3+1=4.
So the equation is y=1n^2+3n+4 or y=n^2+3n+4.
What is the value of W?
5 units
7 units
14 units
15 units
Answer:
5 units!
Step-by-step explanation:
Because Rectangle Perimeter = 2(a+b)
a=2w-1, b=w
2(2w-1+w)=28
3w-1=14
3w=15
w=5
So the answer is 5! 5! 5! A!A!A!
Fighting!! o(≧o≦)o