А) 2 1/2 * 2 - 7 = 5/2 * 2 - 7 = 5 - 7 = - 2
б) 1 1/3 * (-9/16) = 4/3 * (-9/16) = - (1*3)/(1*4) = - 3/4
в) 3 1/3 * (-7/100) = 10/3 * (-7/100) = - (1*7)/(3*10) = - 7/30
а) (-1 1/3) * 9/10 = (-4/3) * 9/10 = - (2*3)/(1*5) = - 6/5 = - 1 целая 1/5
б) (-2/7) * 3 1/2 = (-2/7) * 7/2 = - 1