Pre-Algebra Examples

 $\begin{array}{r} l = & x \\ w = & 3 x + 90 \end{array}$

Step 1

The perimeter of a rectangle is equal to the sum of all sides of the rectangle.

$l e n g t h + l e n g t h + w i d t h + w i d t h = 2 \cdot (l e n g t h) + 2 \cdot (w i d t h)$

Step 2

Substitute the values of the length $l = x$ and width $w = 3$ into the formula for the perimeter of a rectangle.

$2 \cdot x + 2 \cdot 3$

Step 3

Multiply $2$ by $3$ .

$2 x + 6 x + 90$