Answer
$l=8x^2-12x+4$
Work Step by Step
The Area of the rectangle is, $A=l \times w$, whereas $l$ is a length of the rectangle and $w$ is the width of the rectangle.
To find the the length $l$, we can divide both sides of the formula by $w$.
$A/w=l$.
Therefore,
$\begin{array}{lllll}
\underline{-3/4}| & 8 & -6 & -5 & 3\\
& & -6 & 9 & -3\\
\hline & & & & \\
& 8 & -12 & 4 & 0
\end{array}$
$(8x^{3}-6x^2-5x+3)\div(x+3/4)=8x^2-12x+4$.
There by dividing the area by width we can get the length.
$l=8x^2-12x+4$
