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x in (-oo:+oo)
43/42 = x+6/7 // - x+6/7
43/42-x-(6/7) = 0
43/42-x-6/7 = 0
1/6-x = 0 // - 1/6
-x = -1/6 // * -1
x = 1/6
x = 1/6
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