
John M. answered 03/24/21
Math Teacher/Tutor/Engineer - Your Home, Library, MainStreet or Online
The key here is to get the formula correct.
(x+45)(30-4x) will yield the maximum amount trees per acre that will yield 4 more bushels per acre than today's yield.
F(x) = (x+45)(30-4x)
= 30x - 4x^2 + 1350 - 180x
= -4x^2 - 150x - 1350 This a a parabola that opens downward.
The maximum point is (-18.75, 2756.25)
which means he should subtract 19 trees per acre that will yield the maximum yield
or 26 trees per acre.