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x in (-oo:+oo)
3/10 = x/250 // - x/250
3/10-(x/250) = 0
3/10-1/250*x = 0 // - 3/10
-1/250*x = -3/10 // : -1/250
x = -3/10/(-1/250)
x = 75
x = 75
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