<span>7(123-4x)=749
7 * 123 = 861
7 * 4х = 28х
861 - 28Х = 749
861 - 749 = 28Х
112 = 28Х
112 : 28 = 4
Ответ: Х = 4
Проверка.
</span>7(123-4*4)=749
<span>7(123-16)=749</span>
7 * 107 = 749.
1-(62-53)/5=1-9/5=-4/5
147/11+(224/11-19)=(147/11+224/11)-19=371/11-19=(371-209)/11=162/11
2/15+45/15=47/15
-10 + 26 = 16 или -15 + 29 = 16