What is a good method for estimating the thickness of each coin?

Which graph represents the equation y =4x

Can someone me with my math problem pls my teacher is on my back about this

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.