the area of a rectanguar wall is 90 square feet its length is 8ft longer than twice the width. Find the Lenghtand width of the rectangal?

Question

Help! Quick!

Answer 1

Area = Length x Width, so:

 

90 = (2w + 8) * w

90 = 2w² + 8w

90−(2w²+8w)=2w²+8w−(2w²+8w)

−2w²−8w+90=0

Factor the equation:

−2(w−5)(w+9)=0

 

w = 5 or -9

 

But since there isn't a negative value in calculating area, Width would have to be 5.

 

2(5) + 8 = L  so L = 18

 

W = 5

L = 18

Answer 2

Let's consider

 

width=ww

length=2w + 8

 

Area=length * width

 

90 =(2w+8)w

 

90 =2w^2+8w

 

2w^2+8w -90=0

 

w^2 +4w -45=0   dividing equation with 2

 

now factoring it

 

(w+9)(w-5)=0

 

w=-9  or w=5

 

width cannot be negative

 

so width=w=5 feet

 

length=2w+8=2(5)+8=10+8=18 feet