Am I right or wrong??

Given that (x-3) is a factor of f(x)=x^3+ax^2-x-6, find a and hence the number of real roots or the equation f(x)=0

One side of a rectangle is 7 feet shorter than seven times the other side. find the length of the shorter side if we also know that the perimeter of the rectangle is 306 feet.

Based on the figures as marked, /\rqs = —