Answer:
A
Step-by-step explanation:
We have the equation:

Take the derivative of both sides with respect to x:
![\frac{d}{dx}[x^2+xy-3y]=\frac{d}{dx}[3]](https://tex.z-dn.net/?f=%5Cfrac%7Bd%7D%7Bdx%7D%5Bx%5E2%2Bxy-3y%5D%3D%5Cfrac%7Bd%7D%7Bdx%7D%5B3%5D)
Implicitly differentiate:

Solve for dy/dx:

Divide:

To find dy/dx at (2, 1), substitute 2 for x and 1 for y. So:

Hence, our answer is A.
3/4 divide by 5 is equal to 3/20
1. -11 2.-3
Make sure to simplify the equation..
example: 3(2x - 7) = 6x - 21
because 3 x 2 = 6 and 3 x 7 = 21
Answer: H. 139.50
Step-by-step explanation:
Multiply 9 by 8 first and you get 72. Then multiply 9 by 7.5 and you get 67.5 then add 72 and 67.5 and you get 139.5 or 139.50
10000:100*11=1100 income per year
21000-10000=11000 need to have income
11000:1100=10 years will pass time