Question

find the perimeter of the rectangle.

Explanation:

Step1: Recall perimeter formula

The perimeter $P$ of a rectangle is $P = 2(l + w)$ where $l$ is the length and $w$ is the width. Here, $l=3x$ and $w = x - 7$.

Step2: Substitute values into formula

$P=2(3x+(x - 7))$.

Step3: Simplify inside parentheses

$3x+(x - 7)=3x+x - 7=4x - 7$.

Step4: Multiply by 2

$P = 2(4x - 7)=8x-14$.

Answer:

$8x - 14$