Question

the area is 21 what is width and length if length of a rectangle is 8centimers less than 5 times its width.

Answer 1

W = width
L = length
L = 5w-8
Area = (5w-8)(w)
21= (5w-8)(w)
21= 5w^2 -8w
0 = 5w^2 -8w -21
= (5w + 7)(w- 3)

w = -7/5 Or w= 3
But it can't be negative cause it is a width, so it can only be 3

Sub in 5w- 8
= 5(3) - 8
= 15 - 8
= 7

Check (5(3) - 8) (3) (Looking for area)
= (15-3) (3)
= (7)(3)
21

Answer 2

thank u

Answer 3

You are welcome :)

Answer 4

wait what would be the length

Answer 5

@hikat

Answer 6

The length will be the sub in bit, because we know that the length = 5w - 8
So, we just need to sub in the width(which is 3) in, and the answer will be the length