The length of the rectangle is 3 times its width. If the width of the rectangle is reduced by 6 cm

The length of the rectangle is 3 times its width. If the width of the rectangle is reduced by 6 cm, then its area will decrease by 144 cm2. Find the original width of the rectangle.

1. Take x as the initial width of the rectangle. The length of the rectangle is 3 cm.

2. The area of this rectangle is 3x ^ 2 cm ^ 2.

3. The area of a rectangle with a width reduced by 6 centimeters 3x (x – 6) cm ^ 2 =

(3x ^ 2 – 18x) cm ^ 2;

4. Let’s compose the equation:

3x ^ 2 – (3x ^ 2 – 18x) = 144;

18x = 144;

x = 8 centimeters.

Answer: The original width of the rectangle is 8 centimeters.