6(2х + 5) - 7х = 17
12х + 30 - 7х = 17
5х = 17 - 30
5х = -13
х = -13/5
х = -2 целые 3/5
х = -2,6
3х + 6/11 = 0
3х = -6/11
х = (-6/11) ÷ 3
х = -6/(11 × 3)
х = -2/11
9х + 9 = 10х + 7
9х -10х = 7 - 9
-х = -2 | : (-1)
х = 2
s/s^2-4+1/2s-4 = s / (s-2)(s+2) + 1 / 2(s-2) = 2s / 2(s-2)(s+2) + (s+2) / 2(s-2)s+2 =
= 2s+s+2 / 2(s-2)(s+2) = 3c+2 / 2(s^2-4)
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