Уравнение 1 класса
3x+9x+23=131
12х=131-23
12х=108 |:12
<span>х=9</span>
=========================================== 14.5
24*9+12*27=540
1)24*9=216
2)12*27=324
3)216+324=540
Ответ: 540
4(-5-y)+y-3(12+5y)+4=0
2y-56+4=0
2y=52
y=26
z=12+5y z=12+130=142
<span>x=-5-y x=-31</span>