SOLUTION: *******A picture frame is 20 cm by 12 cm. There are 84cm^2 of a picture showing. Find the width of the frame.**** please help, i reall need this problem, it my grade

Algebra ->  Customizable Word Problem Solvers  -> Geometry -> SOLUTION: *******A picture frame is 20 cm by 12 cm. There are 84cm^2 of a picture showing. Find the width of the frame.**** please help, i reall need this problem, it my grade      Log On

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Question 41079: *******A picture frame is 20 cm by 12 cm. There are 84cm^2 of a picture showing. Find the width of the frame.**** please help, i reall need this problem, it my grade
Answer by Paul(988) About Me  (Show Source):
You can put this solution on YOUR website!
Let x be the uniform width
EQUATION:
(20-2x)(12-2x)=84
4x%5E2-64x%2B240=84
4x%5E2-64x%2B156=0
x%5E2-16x%2B39=0
x=3 or x=13
Hence, the unifrom width is 3 cm.
Paul.