SOLUTION: The length of a rectangle is 4 times the width. The perimeter is 50 cm. Find the length and width. Can you show me how to do this, maybe by elimination?

Algebra ->  Algebra  -> Rectangles -> SOLUTION: The length of a rectangle is 4 times the width. The perimeter is 50 cm. Find the length and width. Can you show me how to do this, maybe by elimination?      Log On

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Question 550285: The length of a rectangle is 4 times the width. The perimeter is 50 cm. Find the length and width. Can you show me how to do this, maybe by elimination?
Answer by TutorDelphia(193) About Me  (Show Source):
You can put this solution on YOUR website!
l=4w
2l+2w=50 (this is from the perimeter formula 2l+2w=p
You mentioned you wanted to do this using the elimination method. Let's get both equations in good form for that.
l=4w
subtract 4w from both sides
l-4w=0
2l+2w=50
divide both sides by 2
l+w=25
minus
l-4w=0
5w=25 (minus -4w gives us +4w)
w=5
l=20