Выполни действия: а) 3 3/4+ 1 1/2 б) 2 5/6- 1 5/12 в) 4 - 1 2/3 г) 3 2/7-6/7 д) 1 1/3* 4 е) 3 1/4* 2/5 ж) 2 1/4: 3 з) 20: 2 1/2 помогите пожалуста!!!!

а) 3 3/4+ 1 1/2 = 3 3/4 + 1 2/4 = 4 5/4 = 5 1/4б) 2 5/6- 1 5/12 = 2 10/12 - 1 5/12 = 1 5/12в) 4 - 1 2/3 = 3 3/3 - 1 2/3 = 2 1/3г) 3 2/7-6/7 = 2 9/7 - 6/7 = 2 3/7 д) 1 1/3* 4  = 4/3 * 4/1 = 16/3 = 5 1/3е) 3 1/4* 2/5 = 13/4 * 2/5 = 13/2 * 1/5 = 13/10 = 1 3/10 ж) 2 1/4: 3 = 9/4 * 1/3 = 3/4 з) 20: 2 1/2 = 40/2 : 5/2 = 40/2 * 2/5 = 8