Question

Mike repairs televisions. His revenue equals R(h) = 25 + 30h dollars for every h hours he spends repairing televisions. His overhead cost equals C(h) = 5h^2 − 10 dollars.

After how many hours does he break even?

Answer 1

Answer and workings in the attachment below.

Answer 2

`25+30h=5h^2-10\\ 5h^2-30h-35=0\\ 5(h^2-6h-7)=0\\ h^2-6h-7=0\\ h^2+h-7h-7=0\\ h(h+1)-7(h+1)=0\\ (h-7)(h+1)=0\\ h=7 \vee h=-1\\\\ \boxed{h=7}`

After 7 hours.