Question

A student was asked to use the formula For the perimeter Of a rectangle.P =2l+ 2w, To Solve for L. The student came up with the answer P- 2w = 2l. what error did he make ? Explain.

Answer 1

The formula for the perimeter of a rectangle is given by

`P=2l+2w`

The student was asked to solve for length (l) and he came up with the following answer

`P-2w=2l`

Notice that he did not fully solved the equation for length (l)

He needs to separate the length (l) by dividing both sides by 2

`\begin{gathered} (P-2w)/(2)=(2l)/(2) \\ (P-2w)/(2)=l \\ l=(P-2w)/(2) \end{gathered}`

Now, the equation is solved for length (l)