1) 15-10у-36+4у=3у+15
-10у+4у-3у=15-15+36
-9у=36
у=36:(-9)
у= -4
2) 28х-42-5х-20=6х+10+5х
28х-5х-6х-5х=10+42+20
12х=72
х=72:12
х=6
3) 27х-63+24х-33=27х+24
27х+24х-27х=24+63+33
24х=120
х=120:24
х=5
4) 42х-66-13х+78=28х+14
42х-13х-28х=14+66-78
х=2
39:9=4 (ост. 3)
57:10=5 (ост. 7)
31:7=4 (ост. 3)
20:8=2 (ост. 4)
39:5=7 (ост. 2)
87:9=9 (ост. 6)
48:7=6 (ост.6)
63:10=6 (ост. 3)
50:8=6 (ост. 2)
39:10=3 (ост. 9)