5.445 Вычислите: a) 1/2 + 1/3; б) 1 + 2/7; в) 2 + 3/5; г) 3/4 + 4/9; д) 5/9 - 1/6; е) 3/4 - 1/3; ж) 1 + 1/6 + 7/3; з) 9/5 - 5/10; и) 1 1/2 - 3/8; к) 7/6 - 3/15; л) 5 9/10 + 3/12; м) 1 5/9 - 1 1/6; н) 5/11 + 3/5; о) 17/30 - 3/6; п) 17/35 - 4/15.

a) 1/2 + 1/3 = 3/6 + 2/6 = 5/6 б) 1 + 2/7 = 7/7 + 2/7 = 9/7 = 1 2/7 в) 2 + 3/5 = 10/5 + 3/5 = 13/5 = 2 3/5 г) 3/4 + 4/9 = 27/36 + 16/36 = 43/36 = 1 7/36 д) 5/9 - 1/6 = 10/18 - 3/18 = 7/18 е) 3/4 - 1/3 = 9/12 - 4/12 = 5/12 ж) 1 + 1/6 + 7/3 = 6/6 + 1/6 + 14/6 = 21/6 = 7/2 = 3 1/2 з) 9/5 - 5/10 = 18/10 - 5/10 = 13/10 = 1 3/10 и) 1 1/2 - 3/8 = 3/2 - 3/8 = 12/8 - 3/8 = 9/8 = 1 1/8 к) 7/6 - 3/15 = 35/30 - 6/30 = 29/30 л) 5 9/10 + 3/12 = 59/10 + 1/4 = 118/20 + 5/20 = 123/20 = 6 3/20 м) 1 5/9 - 1 1/6 = 14/9 - 7/6 = 28/18 - 21/18 = 7/18 н) 5/11 + 3/5 = 25/55 + 33/55 = 58/55 = 1 3/55 о) 17/30 - 3/6 = 17/30 - 15/30 = 2/30 = 1/15 п) 17/35 - 4/15 = 51/105 - 28/105 = 23/105