Question

Find the length and width of a rectangle whose perimeter is 20 feet and whose area is 21 square feet

Answer 1

Answer:

Length = 3

Width = 7

Step-by-step explanation:

The perimeter is 20 feet

The area is 21 feet

Let x represent the length

Let y represent the width

20 = 2(x+y)

x+y= 20/2

x+y = 10.........equation 1

x × y= 21......equation 2

From equation 1

x= 10-y

Substitute 10-y for x in equation 2

(10-y)y= 21

10y - y^2 = 21

y^2 -10y + 21= 0

After factorization the result will be

(x-3)(y-7)

x-3= 0

x= 0+3

x= 3

y-7= 0

y= 0+7

y= 7

Hence the length is 3 and the width is 7