Question

A square plywood platform has a perimeter which is 11 times the length of a side decrease by 35 find the length of a side (p= 4L)

Answer 1

The rule of the perimeter of the square is

$P=4L$

L is the length of its side

Since the perimeter is 11 times the length decrease by 35

Then multiply L by 11, then subtract 25 from the product

$\begin{gathered} P=11\times L-35 \\ P=11L-35 \end{gathered}$

Substitute the value of P in the rule above

$11L-35=4L$

Add 35 to both sides

$\begin{gathered} 11L-35+35=4L+35 \\ 11L=4L+35 \end{gathered}$

Now, subtract 4L from both sides

$\begin{gathered} 11L-4L=4L-4L+35 \\ 7L=35 \end{gathered}$

Divide both sides by 7

$\begin{gathered} \frac{7L}{7}=\frac{35}{7} \\ L=5 \end{gathered}$

The length of the side of the square is 5 units