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x in (-oo:+oo)
x-3 = (-3/4)*x-(31/8) // - (-3/4)*x-(31/8)
x-((-3/4)*x)+31/8-3 = 0
x+(3/4)*x+31/8-3 = 0
7/4*x+7/8 = 0 // - 7/8
7/4*x = -7/8 // : 7/4
x = -7/8/7/4
x = -1/2
x = -1/2
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