2 2/7*2 5/6- 1 3\4*2 2/7+2 2/7* 2/3
= 2 2/7(2 5/6 - 1 3/4 + 2/3) = 2 2/7 * (17/6 - 7/4 + 2/3) =
= 16/7 * (34/12 - 21/12 + 8/12) = 16/7 * 21/12 = 12/3 = 4