I have a question about Quadratics.?

Question

does anyone know the answer to this question??

The width of a rectangle is 7 m more than the length. Find the width if the area is 60 m2.

12 m
4 m
5 m

thanks so much!!

Answer 1

w = 7 + L --> L = w-7
A = w * L = 60

w * (w-7) = 60
w^2 - 7w = 60
w^2 - 7w - 60 = 0
(w-12)(w+5)=0
w=12, w=-5 (but -5 is extraneous since width is positive)

So w=12

Answer 2

let 1 side b x
then the other side is x+7
so according to the condition
(x+7)x = 60

x^2 + 7x - 60 =0
(x+12)(x-5)=0

x = 5, -12
and x cannot be negative...so the value of x is 5

hence the width of the triangle is 5+7 = 12 m

Answer 3

12 m

Answer 4

that would make the width the length, it is all about semantics

x (x +7) = 60

x^2 + 7x = 60

x^2 + 7x - 60 = 0

(x+12)(x-5)

length =5
width = 12

Answer 5

Let length = L and width = L + 7
L.(L + 7) = 60
L² + 7L - 60 = 0
(L + 12).(L - 5) = 0
L = 5 (positive value)
W = 12
Width = 12 m

Answer 6

It's 5 meters. I'm pretty sure. I just took ten minutes to solve it... Of course, I also write out all my work... Man, thanks, I really needed to practice my math skills. So 5 m, k?