Answer
$24x^{2}$ + 58x -65
Work Step by Step
Given the areas, we subtract both areas by one another.
($25x^{2}$ + 40x + 16)-($x^{2}$ - 18x + 81)
We distribute the negative sign to the second bracket and get
$25x^{2}$ + 40x + 16 - $x^{2}$ + 18x - 81
We add like terms together to simplify the polynomial.
$25x^{2}$ - $x^{2}$ + 18x + 40x + 16 - 81
$24x^{2}$ + 58x - 65