№2 Найдите значение выражения: 1) -34 + 18 + (-20) + (-16) + 42; 2) -4/7 * 5 3/8 - 7/4; 3) 6/13 * 3.8 - 3.8 * 7/13

1) -34 + 18 + (-20) + (-16) + 42 = -34 + 18 - 20 - 16 + 42 = (-34 - 20 - 16) + (18 + 42) = -70 + 60 = -10 2) -4/7 * 5 3/8 - 7/4 = -4/7 * 43/8 - 7/4 = -4/7 * 43/8 - 7/4 = -43/14 - 7/4 = - (43/14 + 7/4) = - (86/28 + 49/28) = -135/28 = -4 23/28 3) 6/13 * 3.8 - 3.8 * 7/13 = 3.8 * (6/13 - 7/13) = 3.8 * (-1/13) = -3.8/13 = -38/130 = -19/65 Ответ: 1) -10 2) -4 23/28 3) -19/65