Calculați:a)2 2/9-19/15; b)2 5/8-47/20; c)3 5/6-51/16; d)2 1/6-40/27; e)3 1/6-2 3/8;f)4 2/15-3 1/6; g)2 5/6-2 7/10; h)2 5/18-1 5/12.​