Найдите сумму: 1) 4 5/9 + 7 1/6; 2) 6 11/12 + 8 13/18; 3) 2 3/16 + 1 7/24 + 3 1/12.

1) 4 5/9+7 1/6 =11+5/9+1/6 =11+(5*2+1*3)/18 =11+(10+3)/18=11+13/18=11 13/18;2) 6 11/12+8 13/18=14+11/12+13/18=14+(11*3+13*2)/36=14+(33+26)/36=14+59/36=15 23/36; 3) 2 3/16 + 1 7/24 + 3 1/12=6+3/16+7/24+1/12=6+(3*3+7*2+1*4)/48=6+(9+14+4)/48=6 + 27/48=6 9/16.