SOLUTION: The length of a rectangle is 2 ft less than 3 times it's width. The perimeter is 12 ft. Find the length of the rectangle.

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Question 828080: The length of a rectangle is 2 ft less than 3 times it's width. The perimeter is 12 ft. Find the length of the rectangle.
Answer by TimothyLamb(4379) About Me  (Show Source):
You can put this solution on YOUR website!
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x = 3y - 2
2x + 2y = 12
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put the system of linear equations into standard form:
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x - 3y = -2
2x + 2y = 12
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copy and paste the above linear system in standard form into this matrix-method solver:
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solution:
x = 4 ft
y = 2 ft
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system matrix
1 -3
2 2
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inverse of system matrix
0.25 0.375
-0.25 0.125
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determinant of system matrix = 8
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