Is this graph a function?

What is the first step of an indirect proof of a number that is divisible by two

Suppose that the price p, in dollars, and the number of sales, x, of a certain item follow the equation 4 p plus 4 x plus 2 pxequals56. suppose also that p and x are both functions of time, measured in days. find the rate at which x is changing when xequals2, pequals6, and startfraction dp over dt endfraction equals1.5.

Which choice has the correct steps in graphing the solution set to the following inequality? -45_> 20x-5y