Answer:
Option A is correct
equation
could be used.
Step-by-step explanation:
Given: The length of a rectangle
is 14 inches and perimeter of rectangle is 42 inches.
Perimeter(P)of a rectangle in inches is given by:
; where
is the length of the rectangle and w is the width of the rectangle.
Substitute the value of P=42 inches , w =x inches and
inches in the above formula we get;

Divide by 2 on both sides we get;

On simplify, we get;
x = 21-14 = 7 inches
therefore, the width of the rectangle is, x = 7 inches
Check :
Substitute the value of x =7 in option A.


42 = 42
Hence, the only equation that could be used to find the width, x is, 