Answer :
According to the question it's given that,
A rectangle's perimeter and its area have the same numerical value. The length of the rectangle is 6 centimeters.
Required Formulas,
perimeter of rectangle is 2(l+ b)
Area of rectangle = l × b
Also, Length of rectangle is 6 cm.
Perimeter of rectangle
2(6 + x)
12 + 2x
Area of rectangle
l × b
6 × x
6x
Now, A rectangle's perimeter and its area have the same numerical value.
Perimeter of rectangle = Area of rectangle
12 + 2x = 6x (required equation)
Therefore this is the required equation to find the width of the rectangle.