Plz help, its really easy:its mapping diagrams, fill in the blanks

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.

The function f(x) is shown in this graph the function g(x)=6x

The weight of a full steel bead tire is approximately 800 grams, while a fighter wheel weighs only 700 grams. what is the weight of each tire in pounds?