The area of a poster board is (x2 + 9x − 10) square inches. Find the dimensions of the poster board if x = 13. The dimensions of the poster board are |

I asume you mean \({x}^{2}+9x-10\), so I will go with that.

\({x}^{2}+9x-10\)

Subsitute \(x\) for 13.

\({13}^{2}+9\times13-10\)

\(169+9\times13-10\)

\(169+117-10\)

\(286-10\)

\(276\)

x² - 9x + 10 can be factored as (x - 1)*(x + 10) so the side lengths will be x-1 (= 12 in²) and x+10 (=23in²)