25. The perimeter of a rectangle is equal to twice the sum of its length and its width. One

rectangle has a length of 13 inches and a perimeter of 42 inches. Write an equation that can

be used to find the width, w, of the rectangle.

The equation that can be used to find the width is 2 (13 + w) = 42

The width of the rectangle is 8 inches

Step-by-step explanation:

The formula of the perimeter of a rectangle is P = 2 (l + w), where l is its length and w is its width

∵ One rectangle has a length of 13 inches

∴ l = 13 inches

∵ Its perimeter is 42 inches

∴ P = 42 inches

- Substitute the values of l and P in the formula of the perimeter

∵ 42 = 2 (13 + w)

The equation that can be used to find the width is 2 (13 + w) = 42

To find W divide both sides by 2

∴ 21 = 13 + w

- Subtract 13 from both sides

∴ 8 = w

The width of the rectangle is 8 inches