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
where \(P\) stands for perimeter, \(l\) for length and \(w\) for width. We can solve this problem using the equation:
Check whether \(1.4\) is a solution for \(w\) of this equation.