Answer:
-1,512,390
Step-by-step explanation:
Given
a1 = 15

Let us generate the first three terms of the sequence

For 

Hence the first three terms ae 15, 8, 1...
This sequence forms an arithmetic progression with;
first term a = 15
common difference d = 8 - 15 = - -8 = -7
n is the number of terms = 660 (since we are looking for the sum of the first 660 terms)
Using the formula;
![S_n = \frac{n}{2}[2a + (n-1)d]\\](https://tex.z-dn.net/?f=S_n%20%3D%20%5Cfrac%7Bn%7D%7B2%7D%5B2a%20%2B%20%28n-1%29d%5D%5C%5C)
Substitute the given values;
![S_{660} = \frac{660}{2}[2(15) + (660-1)(-7)]\\S_{660} = 330[30 + (659)(-7)]\\S_{660} = 330[30 -4613]\\S_{660} = 330[-4583]\\S_{660} = -1,512,390](https://tex.z-dn.net/?f=S_%7B660%7D%20%3D%20%5Cfrac%7B660%7D%7B2%7D%5B2%2815%29%20%2B%20%28660-1%29%28-7%29%5D%5C%5CS_%7B660%7D%20%3D%20330%5B30%20%2B%20%28659%29%28-7%29%5D%5C%5CS_%7B660%7D%20%3D%20330%5B30%20-4613%5D%5C%5CS_%7B660%7D%20%3D%20330%5B-4583%5D%5C%5CS_%7B660%7D%20%3D%20-1%2C512%2C390)
Hence the sum of the first 660 terms of the sequence is -1,512,390
C it’s wrong so don’t listen to me
Answer:
(8, 11 )
Step-by-step explanation:
Given the 2 equations
2x + 2y = 38 → (1)
y = x + 3 → (2)
Substitute y = x + 3 into (1)
2x + 2(x + 3) = 38 ← distribute and simplify left side
2x + 2x + 6 = 38
4x + 6 = 38 ( subtract 6 from both sides )
4x = 32 ( divide both sides by 4 )
x = 8
Substitute x = 8 into (2) for corresponding value of y
y = 8 + 3 = 11
Solution is (8, 11 )
Answer:
18.67 m/s²
Step-by-step explanation:
a = ∆v/ t
a= v - u/t
a = 2.8 - 0 / 0.15
a = 2.8 / 0.15
a = 18.67 m/s²
Answer:
Equation in slope-intercept form that goes through (12, 4) and (20,8) is: 
Step-by-step explanation:
Given two points are:

Slope intercept form of line is given as:

Here m is the slope of the line and b is the y-intercept.
Slope of a line is calculated by the formula:

Putting the values

Putting the value of slope in slope-intercept form we get

To find the value of b, any one point will be put in the equation
Putting the first point (12,4) in the equation

Putting the value of b

Hence,
Equation in slope-intercept form that goes through (12, 4) and (20,8) is: 