Question 71907
If you factor x^2 + 18x + 81 you will have a product of factors. These factors represent the sides, which if multiplied become the area of x^2 + 18x + 81. So we need to find 2 numbers which add to 18 and multiply to 81; these 2 numbers are 9 and 9.
So x^2 + 18x + 81 factors to (x+9)(x+9). (x+9) is the length of the new sides, where x is the original length. The lengths of all of the sides were increased by 9, not 6 and 8, so this shows he was wrong.