Make f the subject of the formula d= 3(1-f) / f - 4

Acertain company's main source of income is a mobile app. the company's annual profit (in millions of dollars) as a function of the app's price (in dollars) is modeled by p(x)=-2(x-3)(x-11)p(x)=−2(x−3)(x−11) which app prices will result in \$0$0 annual profit? enter the lower price first.