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x in (-oo:+oo)
x+(2.1/11)*x+12 = x+(2.1/12)*x+11 // - x+(2.1/12)*x+11
x+(2.1/11)*x-x-((2.1/12)*x)-11+12 = 0
x+(2.1/11)*x-x-0.175*x-11+12 = 0
0.01590909*x+1 = 0 // - 1
0.01590909*x = -1 // : 0.01590909
x = -1/0.01590909
x = -62.85714645
x = -62.85714645
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