<span>9•(7512-c)=34722</span>
<span>7512-с=34722:9</span>
<span>7512-с=3858</span>
<span>с=7512-3858</span>
<span>с=3654</span>
<span>
</span>
<span>8•a+4097=5081</span>
<span>8*а=5081-4097</span>
<span>8*а=984</span>
<span>а=984:8</span>
<span>а=123</span>
(28+7)-5=30
1)28+7=35
2)35-5=30
189-((63:3)+60+(9*4)))=72