Question

solving equations using perimeter & area of rectangles quiz (8.8c*)
the perimeter and area of the rectangle below is the same. if the length is 7 cm, which equation is correct to find the width of the rectangle?
7 cm
7 + 7 + w + w = 2w
7 + 7 + w + w = 7w
7 + w = 7w
7 + w = 2w

Explanation:

Step1: Recall perimeter formula

The perimeter $P$ of a rectangle is $P = l + l+w + w=2l + 2w$, with $l = 7$, so $P=7 + 7+w + w$.

Step2: Recall area formula

The area $A$ of a rectangle is $A=l\times w$, with $l = 7$, so $A = 7w$.

Step3: Set perimeter equal to area

Since $P = A$, we have $7 + 7+w + w=7w$.

Answer:

$7 + 7+w + w=7w$