14.
1. 7 × 7 = 49
2. 7 × 3 × 3 = 63
3. 7 × 3 × 4 = 84
4. 7 + 3 + 4 = 14
Hope that helps! Feel free to ask for a more explanation, if needed.
Answer:
can't see the image clearly
Do u want the first or second derivative
df/dx= 10-2y, df/dy= -2y+14,
then second deriv is df/dxdy=-2
df/dydx=0