1)х=12 5/12 +7 1/4

х=12 5/12 +7 4/12=19 9/12

2) х-5 7/9=3 5/12 + 2 3/4

х-5 7/9=3 5/12 + 2 9/12=6 2/12

х=6 2/12 + 5 7/9

х=6 6/36 + 5 28/36=11 34/36