Calc word problem

Question

A farmer finds that if she plants 95 trees per acre, each tree will yield 55 bushels of fruit. She estimates that for each additional tree planted per acre, the yield of each tree will decrease by 3 bushels. How many trees should she plant per acre to maximize her harvest?

Answer 1

t represents each additional tree

 

yield = (95 + t)(55 - 3t)

 

multiply and determine vertex.