D because it is a decimal (lower than 0)
To solve this we can make it into an equation, which looks like this
y = 2x (for Rebecca)
y = x + 10 (for Alice)
The we subtract one equation from the other to solve
0 = x - 10
10 = x
x = 10
Now we replace x in whichever equation and we get 20
So, each girl will read 20 books for them to be at the same book.
Hope this helps, remember that Jesus loves you
Answer:
3
Step-by-step explanation:
It's given that ΔDEF ∼ΔXYZ . So the corresponding sides of both triangles will be proportional to each other.
![= > \frac{de}{xy} = \frac{ef}{yz} = \frac{df}{xz}](https://tex.z-dn.net/?f=%20%20%3D%20%20%3E%20%5Cfrac%7Bde%7D%7Bxy%7D%20%20%3D%20%20%20%20%5Cfrac%7Bef%7D%7Byz%7D%20%20%3D%20%20%5Cfrac%7Bdf%7D%7Bxz%7D%20)
DE = 4 ; XY = 4(n + 1) ; EF = 5 ; YZ = 7n - 1
Putting all these values gives ,
![\frac{4}{4(n + 1)} = \frac{5}{7n - 1}](https://tex.z-dn.net/?f=%20%5Cfrac%7B4%7D%7B4%28n%20%2B%201%29%7D%20%20%3D%20%20%5Cfrac%7B5%7D%7B7n%20-%201%7D%20)
![= > \frac{1}{n + 1} = \frac{5}{7n - 1}](https://tex.z-dn.net/?f=%20%3D%20%20%3E%20%20%5Cfrac%7B1%7D%7Bn%20%2B%201%7D%20%20%3D%20%20%5Cfrac%7B5%7D%7B7n%20-%201%7D%20)
![= > 7n - 1 = 5(n + 1)](https://tex.z-dn.net/?f=%20%3D%20%20%3E%207n%20-%201%20%3D%205%28n%20%2B%201%29)
![= > 7n - 1 = 5n + 5](https://tex.z-dn.net/?f=%20%3D%20%20%3E%207n%20-%201%20%3D%205n%20%2B%205)
![= > 7n - 5n = 5 + 1](https://tex.z-dn.net/?f=%20%3D%20%20%3E%207n%20-%205n%20%3D%205%20%2B%201)
![= > 2n = 6](https://tex.z-dn.net/?f=%20%3D%20%20%3E%202n%20%3D%206)
![= > n = \frac{6}{2} = 3](https://tex.z-dn.net/?f=%20%3D%20%20%3E%20n%20%3D%20%20%5Cfrac%7B6%7D%7B2%7D%20%20%3D%203)
Answer:
C
Step-by-step explanation:
The average rate of change of f(x) in the closed interval [ a, b ] is
![\frac{f(b)-f(a)}{b-a}](https://tex.z-dn.net/?f=%5Cfrac%7Bf%28b%29-f%28a%29%7D%7Bb-a%7D)
Here [ a, b ] = [ - 10, 10 ], thus
f(b) = f(10) = 10² + 9(10) + 18 = 100 + 90 + 18 = 208
f(a) = f(- 10) = (- 10)² + 9(- 10) + 18 = 100 - 90 + 18 = 28, thus
average rate of change =
=
= 9