Answer
a) $W=\dfrac{A}{L}$
b) $L=\dfrac{A}{W}$
Work Step by Step
a) Using the properties of equality, in terms of $
W
,$ the given formula, $
A=LW
,$ is equivalent to
\begin{array}{l}\require{cancel}
\dfrac{A}{L}=\dfrac{LW}{L}
\\\\
\dfrac{A}{L}=W
\\\\
W=\dfrac{A}{L}
.\end{array}
b) Using the properties of equality, in terms of $
L
,$ the given formula, $
A=LW
,$ is equivalent to
\begin{array}{l}\require{cancel}
\dfrac{A}{W}=\dfrac{LW}{W}
\\\\
\dfrac{A}{W}=L
\\\\
L=\dfrac{A}{W}
.\end{array}