Помогите решить дроби -13/30+7/18*(-6/35)
3/25:6/35-3
14/15*10/21-2

  - 13/30 + 7/18 * (-6/35) = -13/30 - 1/3 * 1/5 = -13 / 30 - 1/15 = - (13/30 + 2/30) = 
= - (15/30) = - 1/2
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3/25 : 6/35 - 3 = 3/25 * 35/6 - 3 = 1/5 * 7/2 - 3 = 7/10 - 3  = - (3 - 7/10) = -2  3/10
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14/15 * 10/21 - 2 = 2/3 * 2/7 - 2 = 4/21-2=-(2 - 4/21) = - 1    17/21