###### Exercise 54

A rectangular frame’s perimeter is \(7\) feet. If its length is \(2.1\) feet, suppose we want to find how long is its width. A rectangle’s perimeter formula is

\begin{equation*}
P=2(l+w)
\end{equation*}

where \(P\) stands for perimeter, \(l\) for length and \(w\) for width. We can solve this problem using the equation:

\begin{equation*}
7=2(2.1+w)
\end{equation*}

Check whether \(1.4\) is a solution for \(w\) of this equation.

Yes

No