Difference is subtract so 400-148=252
Answer:
7. Option B:40 is the correct answer.
8. Option D: y = 40x+75 is the correct answer.
Step-by-step explanation:
Given that:
Charges per hour = $40
Fee charged by repairman = $75
x = number of hours
y = total fee
According to given statement;
y = 40x+75
The standard equation is
y = mx + b
On comparing;
Slope of the line is given by m, therefore
Slope = m = 40
Hence,
7. Option B:40 is the correct answer.
8. Option D: y = 40x+75 is the correct answer.
Answer:
B
Step-by-step explanation:
Answer with Step-by-step explanation:
We are given that u and v are functions of x and both are differentiable at x=0
a.We have to find the values of 
Using this formula
Then , we get
![[\frac{d(uv)}{dx}]_{x=0}=u'(0)v(0)+u(0)v'(0)=7(2)+4(1)=14+4=18](https://tex.z-dn.net/?f=%5B%5Cfrac%7Bd%28uv%29%7D%7Bdx%7D%5D_%7Bx%3D0%7D%3Du%27%280%29v%280%29%2Bu%280%29v%27%280%29%3D7%282%29%2B4%281%29%3D14%2B4%3D18)
![[\frac{d(uv)}{dx}]_{x=0}=18](https://tex.z-dn.net/?f=%5B%5Cfrac%7Bd%28uv%29%7D%7Bdx%7D%5D_%7Bx%3D0%7D%3D18)
b.
![[\frac{d(u/v)}{dx}]_{x=0}=\frac{u'(0)v(0)-u(0)v'(0)}{v^2(0)}=\frac{7(2)-4(1)}{2^2}=\frac{14-4}{4}=\frac{10}{4}=\frac{5}{2}](https://tex.z-dn.net/?f=%5B%5Cfrac%7Bd%28u%2Fv%29%7D%7Bdx%7D%5D_%7Bx%3D0%7D%3D%5Cfrac%7Bu%27%280%29v%280%29-u%280%29v%27%280%29%7D%7Bv%5E2%280%29%7D%3D%5Cfrac%7B7%282%29-4%281%29%7D%7B2%5E2%7D%3D%5Cfrac%7B14-4%7D%7B4%7D%3D%5Cfrac%7B10%7D%7B4%7D%3D%5Cfrac%7B5%7D%7B2%7D)
![[\frac{d(u/v)}{dx}]_{x=0}=\frac{5}{2}](https://tex.z-dn.net/?f=%5B%5Cfrac%7Bd%28u%2Fv%29%7D%7Bdx%7D%5D_%7Bx%3D0%7D%3D%5Cfrac%7B5%7D%7B2%7D)
c.
![[\frac{d(v/u)}{dx}]_{x=0}=\frac{v'(0)u(0)-v(0)u'(0)}{u^2(0)}=\frac{1(4)-7(2)}{4^2}](https://tex.z-dn.net/?f=%5B%5Cfrac%7Bd%28v%2Fu%29%7D%7Bdx%7D%5D_%7Bx%3D0%7D%3D%5Cfrac%7Bv%27%280%29u%280%29-v%280%29u%27%280%29%7D%7Bu%5E2%280%29%7D%3D%5Cfrac%7B1%284%29-7%282%29%7D%7B4%5E2%7D)
![[\frac{d(v/u)}{dx}]_{x=0}=\frac{-10}{16}=\frac{-5}{8}](https://tex.z-dn.net/?f=%5B%5Cfrac%7Bd%28v%2Fu%29%7D%7Bdx%7D%5D_%7Bx%3D0%7D%3D%5Cfrac%7B-10%7D%7B16%7D%3D%5Cfrac%7B-5%7D%7B8%7D)
d.
![[\frac{d(-6v-9u)}{dx}]_{x=0}=-6v'(0)-9u'(0)=-6(1)-9(7)=-6-63=-69](https://tex.z-dn.net/?f=%5B%5Cfrac%7Bd%28-6v-9u%29%7D%7Bdx%7D%5D_%7Bx%3D0%7D%3D-6v%27%280%29-9u%27%280%29%3D-6%281%29-9%287%29%3D-6-63%3D-69)
![[\frac{d(-6v-9u)}{dx}]_{x=0}=-69](https://tex.z-dn.net/?f=%5B%5Cfrac%7Bd%28-6v-9u%29%7D%7Bdx%7D%5D_%7Bx%3D0%7D%3D-69)
1) m-13=7
2)m-13=7
m-13+13=7+13
m=20
so he had $20 he spent $13 so $7 was left!
BRAINLIEST???
