The length of a rectangular footprint of a residence is 7 more than its width. If the area of the rectangle is 8.2m(squared), what is the perimeter?

Question

Anwser must be rounded to the nearest metre

Answer 1

Area = L x W

Let width be equal to x

L= x + 7

x (width) multiplied by (x+7) (length) = 8.2 m² (area)

x² + 7x = 8.2

x² + 7x -8.2 = 0

Use the quadratic equation to solve for x.

a= 1

b=7

c= -8.2

-7 +/- √( (7²) - 4 (1) (-8.2) ) all divided by 2 (1)

-7 +/- √49 + 32.8 all divided by 2

-7 +/- 9.044 all divided by 2

(-7 + 9.044) /2 and (-7 -9.044) /2

Given lengths can only be positive numbers, the equation (-7 + 9.044)/2 is the only one that applies.

x= 2.044

Width = 2.044

Length = 2.044 + 7 = 9.044

Perimeter = 2L +2 W

2 (2.044) + 2 (9.044)

4.088 + 18.088

22.176 meters is your perimeter.

Rounded to nearest meter is 22 meters.