Q:

The length of a rectangle is 1 ft less than twice the width, the area of the rectangle is 21 ft squared. What’s the length

Accepted Solution

A:
Answer:The length of the rectangle is 6 feetStep-by-step explanation:Given as :The length of rectangle is 1 feet less than twice the widthSo, let The width of rectangle = w feetThe length of rectangle = ( 2 w - 1 )  feetThe area of the rectangle = 21 feet²Now, ∵ The area of the rectangle = length × widthOr, 21 feet² =  ( 2 w - 1 ) feet × w feetor, 21 = 2 w² - wor, 2 w² - w - 21 = 0or, 2 w² + 6 w - 7 w - 21 = 0or , 2 w ( w + 3 ) - 7 ( w + 3 ) = 0or, ( w + 3 ) ( 2 w - 7 ) = 0So, w = - 3 feet , [tex]\frac{7}{2}[/tex] feet here we consider only positive value of w i.e  [tex]\frac{7}{2}[/tex] feet ∴ The length of rectangle = ( 2 w - 1 )  feetor,  The length of rectangle = 2 × [tex]\frac{7}{2}[/tex]  - 1Or, The length of rectangle = 7 - 1 = 6 feetHence The length of the rectangle is 6 feet , Answer