SOLUTION: the perimeter of a rectangle is 80m.the length is decresed by 2m and width is increased by 2m.By doing this the area of a rectangle will be increased by 36 sq.m. What is the length

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: the perimeter of a rectangle is 80m.the length is decresed by 2m and width is increased by 2m.By doing this the area of a rectangle will be increased by 36 sq.m. What is the length      Log On


   

Question 631663: the perimeter of a rectangle is 80m.the length is decresed by 2m and width is increased by 2m.By doing this the area of a rectangle will be increased by 36 sq.m. What is the length and width?
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
let length be l & width be w
2(l+w)= 80 perimeter
l+w = 40
new length = (l-2)
new width = (w+2)
New area - old area = 36
(l-2)(w+2)-lw=36
lw+2l-2w-4-lw=36
2l-2w=40
/2
l-w=20
l+w=40
add both equations
2l=60
l=30
so w=10
The dimensions of rectangle are 30 & 10 m