Answer:
17
Explanation:
Let F be the number of fruit per acre
F = (25 + x) × (41 - x)
F=1025 -25x + 41x -x²
F=-x²+16x+1025
The maximum yield is at the maximum of that expression, which is at
x=8
So apparently she currently has far too many trees per acre. To get the maximum yield, she needs to reduce the number of trees per acre by 8.
So the number of trees per acre for maximum yield is 25-8 = 17.