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x in (-oo:+oo)
21/25 = x/375 // - x/375
21/25-(x/375) = 0
21/25-1/375*x = 0 // - 21/25
-1/375*x = -21/25 // : -1/375
x = -21/25/(-1/375)
x = 315
x = 315
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