20.5 is the answer, have a great day!
X+3y=3
First add subtract the x
3y=-x+3
Then divide 3
Y=-1/3x+1
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Formula
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Area of rectangle = Length x Width
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Find Length
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357 = Length x 17
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Divide by 17 through
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Length = 357 ÷ 7
Length = 51 inches
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Answer: The length of the rectangle is 51 inches
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Plug in 4 for x and solve equation like so. c=2