Answer:
(x + 1)(x + 7)
Explanation:
We can construct the following equation to model the area of the shaded region:
area of shaded = (area of large square) - (area of small square)
A = (x + 4)² - 3²
This can be simplified by executing the exponents, then factoring the resulting expression.
A = (x² + 8x + 16) - 9
A = x² + 8x + 7
A = (x + 1)(x + 7)