Answer :

We can't find the exact area of this rectangle without knowing x.  However, in terms of x, we can expand (4x+3)(2x-1) to get [tex]8x^2+2x-3[/tex] as the area in terms of x.
A = lw
A = (4x + 3)(2x - 1)
A = 8x² - 4x + 6x - 3
A = 8x² + 2x - 3