Answer
$16x^2-9$
Work Step by Step
The area of a rectangle is:
$A=l\times w,$
where $l$ and $w$ are its dimensions.
We are given:
$l=4x+3, w=4x-3.$
We calculate the area using the Sum and Difference of Two terms:
$A=(4x+3)(4x-3)$
$=16x^2-9.$
