А) -5\6+•(-2\15) б) (-5\6+5)•(-2\15) в) -12•3\4-2•5\12 г) -12•(3\4-2)•5\12

а) -5/6 * (-2/15) = -1/3 * (-1/3) = 1/9;

б) (-5/6 + 5) * (-2/15) = (-5/6 + 30/6) * (-2/15) = 25/6 * (-2/15) = 5/3 * (-1/3) = -5/9;

в) -12 * 3/4 - 2 * 5/12 = -36/4 - 10/12 = -9 - 10/12 = -108/12 - 10/12 = -118/12 = -59/6 = -9 5/6;

г) -12 * (3/4 - 2) * 5/12 = -12 * (3/4 - 8/4) * 5/12 = -12 * (-5/4) * 5/12 = 15 * 5/12 = 75/12 =

= 25/4 = 6 1/4.