The formula for this is [tex]9 ^{2} =x(x+24)[/tex]. Simplifying we get [tex]81= x^{2} +24x[/tex] and [tex] x^{2} +24x-81=0[/tex]. Factor that however you see fit (the quadratic formula always works!) to get that x = 3 and -27. Now, the 2 things in math that will NEVER EVER be negative are time and distance/length. Therefore, -27 cannot be the measure of x. It has to be 3.
