Mrs. Math’s research has shown that if 100 apple trees are planted, then

Question

the annual revenue is $90 per tree. If more trees are planted they have less
room to grow and generate fewer apples per tree. As a result, the annual
revenue per tree is reduced by $0.70 for each additional tree planted. How
many trees should be planted to maximize the revenue? Round your
answer appropriately. (Hint: Form a quadratic function)

Answer 1

revenue is #trees * revenue-per-tree
So, if there are x trees more than 100,
r(x) = (100+x)(90-0.70x)
so now just find the vertex of that parabola.