SOLUTION: If the perimeter of a regtangle is 80m and the area is 300 m2 what is the length and width of the rectangle. What is the formula for working out this?

Algebra ->  Rectangles -> SOLUTION: If the perimeter of a regtangle is 80m and the area is 300 m2 what is the length and width of the rectangle. What is the formula for working out this?      Log On


   

Question 567535: If the perimeter of a regtangle is 80m and the area is 300 m2 what is the length and width of the rectangle. What is the formula for working out this?
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
perimeter of recatngle = 2(L+W)
2(L+W)=80
Area of rectangle = L*W
L*W= 300
L= 300/w
substitute L in the first equation
2%28%28300%2FW%29%2BW%29=80

2%28%28300%2BW%5E2%29%2FW%29=80

Multiply by W
2%28300%2BW%5E2%29=+80W
divide by 2

300%2BW%5E2=40W%0D%0A%0D%0A%0D%0A%7B%7B%7BW%5E2-40W%2B300%29=0

W%5E2-30W-10W%2B300=0
W(W-30)-10(W-30)=0
(W-30)(W-10)=0
W= 30 OR 10
The dimensions are 30m by 10m
m.ananth@hotmail.ca