1)8x-7x+142=51
1x= 51-142
1x= -91
2) 8x-7x-142=51
1x=51+142
1x=193
ya raskrila skobki)
1\4-2*1/2*2\3+4\9=1\4-2/3+4\9=3/12-8/12+4/9=4/9-5/12=2/3-5/12=8/12-5/12=3/12=1\4
1)1428:14=102 2)104-102=2 3)35-2=32
(х-3/5)+4/15=7/10
х-3/5+4/15=7/10
х=7/10+3/5-4/15
х=21/30+18/30-8/30
х=31/30
х=1 1/30
285-(х:14-481)=36*6
285-(х:14-481)=216
х:14-481=285-216
х:14-481=69
х:14=69+481
х:14=550
х=550×14
х=7700
Проверка:
(285-(7700÷14-481)):6=36
7700÷14=550
550-481=69
285-69=216
216:6=36
36=36