Найдите значение выражения: a) 6/13 * 39/2, b) 21/11 - 22/3, c) (3/10 + 1/2) * 3/2.

a) (6/13)*(39/2) = (6*39)/(13*2) = 234/26 = 117/13. b) 21/11 - 22/3 = (63 - 242)/33 = -179/33. c) (3/10 + 1/2)*(3/2) = (3/10 + 5/10)*(3/2) = (8/10)*(3/2) = 24/20 = 6/5.