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Question 1130003: The frame of a picture is 30 cm by 34 cm outside and is of uniform width. What is the width of the frame if 252 cm2 of the picture shows?
1) Sketch a relevant graph and define appropriate variables
2) Model the problem (an equation)
3) Solve the model and answer the question.
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! The frame of a picture is 30 cm by 34 cm outside and is of uniform width.
What is the width of the frame if 252 cm2 of the picture shows?
:
let x = the width of the frame
Dimensions of the picture: (30-2x) by (34-2x)
therefore
(30-2x)*(34-2x) = 252 sq/cm
FOIL
1020 - 60x - 68x + 4x^2 = 252
Arrange as a quadratic equation
4x^2 - 128x + 1020 - 252 = 0
4x^2 - 128x + 768 = 0
simplify, divide by 4
x^2 - 32x + 192 = 0
Use the quadratic formula; a=1; b=-32; c=192, but this will factor to
(x-24)(x-8) = 0
Only one solution is reasonable
x = 8 cm is the width of the frame
:
I'll let you do this part
1) Sketch a relevant graph and define appropriate variables
2) Model the problem (an equation)
3) Solve the model and answer the question.
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