Answer:
Width = 10 inches
Step-by-step explanation:
Given the perimeter of a rectangle of 68 inches, and a length that is 14 inches longer than its width.
We can establish the following values to help us solve for the width of a rectangle:
Perimeter (P) = 68 inches
Length (L) = 14 + W inches
Width (W) = unknown
<h3 /><h3><u>Solve for the Width (W)</u></h3>
P = 2(L + W) ⇒ This is the same as P = 2L + 2W, except that 2 is factored out from the right-hand side.
Divide both sides by 2:
![\displaystyle\mathsf{\frac{P}{2}\:=\:\frac{2(L\:+\:W)}{2}}](https://tex.z-dn.net/?f=%5Cdisplaystyle%5Cmathsf%7B%5Cfrac%7BP%7D%7B2%7D%5C%3A%3D%5C%3A%5Cfrac%7B2%28L%5C%3A%2B%5C%3AW%29%7D%7B2%7D%7D)
![\displaystyle\mathsf{\frac{P}{2}\:=L\:+\:W}](https://tex.z-dn.net/?f=%5Cdisplaystyle%5Cmathsf%7B%5Cfrac%7BP%7D%7B2%7D%5C%3A%3DL%5C%3A%2B%5C%3AW%7D)
Substitute the value of the Perimeter and the length (L) into the formula:
![\displaystyle\mathsf{\frac{68}{2}\:=14\:+W\:+\:W}](https://tex.z-dn.net/?f=%5Cdisplaystyle%5Cmathsf%7B%5Cfrac%7B68%7D%7B2%7D%5C%3A%3D14%5C%3A%2BW%5C%3A%2B%5C%3AW%7D)
Combine like terms on the right-hand side, and simplify the left-hand side of the equation:
![\displaystyle\mathsf{34\:=14\:+2W}](https://tex.z-dn.net/?f=%5Cdisplaystyle%5Cmathsf%7B34%5C%3A%3D14%5C%3A%2B2W%7D)
Subtract 14 from both sides:
34 - 14 = 14 - 14 + 2W
20 = 2W
Divide both sides by 2 to solve for the width (W):
![\displaystyle\mathsf{\frac{20}{2}\:=\:\frac{2W}{2}}](https://tex.z-dn.net/?f=%5Cdisplaystyle%5Cmathsf%7B%5Cfrac%7B20%7D%7B2%7D%5C%3A%3D%5C%3A%5Cfrac%7B2W%7D%7B2%7D%7D)
W = 10 inches
Therefore, the width of the rectangle is 10 inches.
<h3 /><h3><u>Double-check:</u></h3>
Verify whether the derived value for the width is correct:
P = 2L + 2W
68 = 2(14 + 10) + 2(10)
68 = 2(34) + 20
68 = 48 + 20
68 = 68 (True statement).
Thus, the length of the rectangle is 34 inches, and the width is 10 inches.