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4/9-((1/3)*x) = 20/99-x // - 20/99-x
x-((1/3)*x)+4/9-(20/99) = 0
(-1/3)*x+x+4/9-20/99 = 0
2/3*x+8/33 = 0 // - 8/33
2/3*x = -8/33 // : 2/3
x = -8/33/2/3
x = -4/11
x = -4/11
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