## Algebra: A Combined Approach (4th Edition)

$20x^{5}$ feet
We are given that the rectangle has a width of $4x^{2}$ feet and a length of $5x^{3}$ feet. We know that the area of a rectangle is calculated as $area=width \times length$ Based on the product rule for exponents, we know that $a^{m}\times a^{n}=a^{m+n}$ (where $m$ and $n$ are positive integers and $a$ is a real number). Therefore, $area=4x^{2}\times5x^{3}=4\times5\times x^{2+3}=20x^{5}$ feet.