2.
3/26+7/39=9/78+14/78=23/78
0,875-(7/12+3/16)=875/100-(28/48+9/48)=875/1000-37/48=5250/6000-4625/6000=625/6000=5/48
4 2/5+3 1/7-6 4/35=22/5+22/7-214/35=154/35+110/35-214/35=50/35=10/7=1 3/7
15-6 3/7-1 2/9=15-45/7-11/9=945/63-405/63-77/63=463/63=7 22/63
3.
10 1/8-(х+0,75)=3 5/32
х+75/100=81/8-101/32
х+75/100=324/32-101/32
х+75/100=223/32
х=223/32-75/100
х=11150/1600-1200/1600
х=9950/1600=199/32=6 7/32
7 1/12-(х-2 5/6)=1 7/8
х-17/6=85/12-15/8
х-17/6=170/24-45/24
х-17/6=125/24
х=125/24+68/24
х=193/24=8 1/24