21. A rectangle has an area of x2 + 3x – 4 and a width of X - 1. What is the length of the rectangle? I A.X + 4 B. X – 4 C. X + 2 D. x - 2

Respuesta :

The area of a rectangle is given by:

[tex]\begin{gathered} A=w\cdot l \\ where \\ w=width_{}=x-1 \\ l=length \\ A=Area=x^2+3x-4 \end{gathered}[/tex]

So:

[tex]\begin{gathered} l=\frac{A}{w} \\ l=\frac{x^2+3x-4}{x-1}=\frac{(x-1)(x+4)}{(x-1)}=x+4 \end{gathered}[/tex]