How do you solve that

Solve each quadratic equation by factoring and using the zero product property. x^2 - 8x + 30 = 3x

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.

(pls ) for which data set would the mean absolute deviation (mad) be a good indicator of variation of the data?