Which expression represents the area of a rectangle whose width is x + 3 and whose

length is 4x - 7?

A. 5x - 4

B. 10x - 8

C. 4x2 - 21

D. 4x2 + 5x - 21

D because (x+3) (4x-7) = 4x ²+5x-21

im guessing you're in algebra dealing with factoring polynomials. basically what i did was use the formula for area which is L*W=A; (length) (width) = area

and then you multiply the two to get D