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.
Answer:
1. 1 min : 2 min
2. 1 min : 4 min
3. 1 : 5
4. 1 : 2
5. 1 hr : 4 hrs
6. 7 p : 10 p
7. 5 : 2 : 3
8. 1 : 3
9. 3 : 5
Step-by-step explanation:
break it down to the lowest, which means to keep dividing it till it can't anymore.
hope that helps
117 times 100 11700 then divide by 200 which is 58.5 %
Chance has 90.72 grams in coins