1.5 2/7=37/7;3 5/16=53/16;8 9/12=105/12;4 7/13=59/13
2.74/6=12 2/6=12 1/3;52/7=7 3/7;93/15=6 3/15=6 1/5;87/11=7 10/11
3.а)12 7/14+6 15/14=18 22/14=19 8/14=19 4/7
б)19-6 5/18=18 18/18-6 5/18=12 13/18
в)9 6/14-3 9/14=8 20/14-3 9/14=5 11/14
4.а)8×(х-6)=45
8х-48=45
8х=45+48
8х=93
х=11,625
45/11,625-6=8
45/5,625=8
8=8
б)(2х+12)÷7=13
2х+12=13×7
2х=91-12
х=79÷2
х=39,5
(2×39,5+12)÷7=13
(79+12)÷7=13
91÷7=13
13=13