Пользуясь сочетательный свойством Вычислите наиболее удобным способом

(-9 * 15) * (-2) = 9 * (15 * 2) = 9 * 30 = 9 * 3 * 10 = 270      (-8 * (-12)) * 5 = 8 * (12 * 5) = 8 * 60 = 8 * 6 * 10 = 480 (3 * (-25)) * 2 = - 3 * (25 * 2) = - 3 * 50 = - 3 * 5 * 10 = - 150 ----------------------------------------------------------------------------------- 1 1/2  * (-5) * (-2/3) = 5 * (3/2 * 2/3) = 5 * 1 = 5 3/8 * (-13) * 2 2/3 = - 13 * (3/8 * 8/3) = - 13 * 1 = - 13 - 1 3/7 * (-9) * (-7/10) = - 9 * (10/7 * 7/10) = - 9 * 1 = - 9 ------------------------------------------------------------------------------------ Пояснения: 1 целая 1/2 = (1*2+1)/2 = 3/2 2 целых 2/3 = (2*3+2)/3 = 8/3 1 целая 3/7 = (1*7+3)/7 = 10/7 (-) * (-) = (+) (-) * (+) = (-)