1. Выполните умножение.

a) (4/6) * (2/5) = (4*2)/(6*5) = 8/30 = 4/15. b) (2 1/10) * (2 7/10) = (21/10) * (27/10) = (21*27)/(10*10) = 567/100 = 5 67/100. c) (1 7/8) * 2 = (15/8) * 2 = (15*2)/8 = 30/8 = 3 6/8 = 3 3/4. d) (2 2/21) * (3 1/2) = (44/21) * (7/2) = (44*7)/(21*2) = 308/42 = 154/21 = 7 7/21 = 7 1/3.