Answer
$\color{blue}{\bf{(a) \dfrac{x}{4}=s }}$
$\color{blue}{\bf{(b) (\dfrac{x}{4})^2 = y }}$
$\color{blue}{\bf{(c) \dfrac{9}{4} \text{ square units} }}$
Work Step by Step
The perimeter $x$ of a square with side lengths $s$ can be modeled with the function: $\bf{x=4s}$
$\bf{\text{(a) }}$ Let's find $s$ in terms of $x$:
$x=4s$
divide by 4
$\color{blue}{\bf{ \dfrac{x}{4}=s }}$
$\bf{\text{(b) }}$ if $y$ is the area of the square, $y$ as a function of $x$ is:
$s^2=y$
substitute $\dfrac{x}{4}$ for $s$
$\color{blue}{\bf{ (\dfrac{x}{4})^2 = y }}$
$\bf{\text{(c) }}$ to find the area of a square with perimeter $x=6$:
$ (\dfrac{6}{4})^2 = y $
$ \dfrac{36}{16} = y $
$\color{blue}{\bf{ \dfrac{9}{4} \text{ square units} }}$
