The perimeter of a rectangle is 104 inches. The width is 6 inches less than 3 times the length. Find out the width of the rectangle.

Let l = the length of the rectangle and let w = the width of the rectangle. Because the width is 6 inches less than 3 times the length, one equation is w = 3l - 6. The formula for the perimeter of a rectangle is 2l + 2w = 104. Substitute the ?rst equation into the perimeter equation for w results in 2l + 2(3l - 6) = 104. Use the distributive property on the left side of the equation: 2l + 6l - 12 = 104. Combine such as words on the left side of the equation: 8l - 12 = 104; add 12 to both sides of the equation: 8l - 12 + 12 = 104 + 12. Simplify to: 8l = 116. Divide both sides of the equation through 8: 8l/8 = 116/8. Thus, the length is l = 14.5 inches and the width is w = 3(14.5) - 6 = 37.5 inches.