When solving an equation with the variable on each side, it does not really matter which side the variable ends up on once it is isolated. why do you have to be more careful with inequalities in this situation?

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.