Вычислите значение выражения. 1) (3(4/9) - 1(16/21)) : 1(11/42) - 1(5/7)

1) (3(4/9) - 1(16/21)) : 1(11/42) - 1(5/7) : 6 =
а) 3(4/9) - 1(16/21) = 3(28/63) - 1(48/63) = 1(43/63).
б) 1(43/63) : 1(11/42) = 106/63 * 42/53 = 4/3 = 1(1/3).
в) 1(5/7) : 6 = 12/7 * 1/6 = 2/7.
г) 1(1/3) - 2/7 = 1(7/21) = 1(1/21).

2) (4(2/3) : 3(1/2) - 3(1/2) : 1(17/18)) = 3/10.
а) 4(2/3) : 3(1/2) = 14/3 * 2/7 = 1(1/3).
б) 3(1/2) : 4(2/3) = 7/2 * 3/14 = 3/4.
в) 1(1/3) - 3/4 = 16/12 - 9/12 = 7/12
г) 7/12 : 1(17/18) = 7/12 * 18/35 = 3/10.