Answer
$\color{blue}{\bf{A(x)=L(x)*W(x)=(x+3)(x-1)}}$
Work Step by Step
The area of a square with side length $x$ is modeled by the function:
$A=x^2$
If $3$in is added to one side, the length, $L$ of the new rectangle is:
$L(x)=x+3$
If $1$in is subtracted from one side, the width, $W$ of the new rectangle is:
$W(x)=x-1$
The area, $A$ of the new rectangle is:
$\color{blue}{\bf{A(x)=L(x)*W(x)=(x+3)(x-1)}}$
