<span><span>5*(c+3)</span> = <span>8*(10-c)</span> -одинаковые знаменатели сокращаются.</span>
<span> 6 6</span>
<span>
</span>
<span>5(с+3)=8(10-с)</span>
<span>5с+15=80-8с</span>
<span>5с+8с=80-15</span>
<span>13с=65</span>
<span>с=65:13</span>
<span>с=5</span>
1)130*6=780
2)741/7=102
3)56,380+325,478=381,858
4)381,858+780=1161,858
5)1161,858+102=1263,858
8/4 = 2
Вот так вот !!!!!!!!!
1 7/12 + 5 6/7 : (2 2/5 - 3 4/7)=19/12+(41/7 :(-41/35))=19/12-5/1=(19-60)/12=-41/12= - 3 5/12