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x in (-oo:+oo)
4/9-x = x+80/99 // - x+80/99
4/9-x-x-(80/99) = 0
4/9-x-x-80/99 = 0
-2*x-4/11 = 0 // + 4/11
-2*x = 4/11 // : -2
x = 4/11/(-2)
x = -2/11
x = -2/11
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