Question 213078
X +y =100,,,,,or  y=100-X
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X/y = 4 + 15/y,,,,,,,cross multiply
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X= 4y +15,,,,,,,substitute
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X= 4(100-X) +15
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X= 400-4X +15
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5X =415
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X=83,,,,,,,,y=100-X=100-83 = 17
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check,,,, 83+17 =100,,,,ok
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83/17 = 4 15/17,,,,,,,ok
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