1) 120+x*3=375 2) 24000 : (x-12)=80 3) x : 26+1654=2610

ответ:
1)120+x*3=375
x*3=375-120
x*3=255
x=3_/255
2)24000/(x-12)=80   |*(x-12)
24000=80(x-12)
24000=80x-12*80
24000=80x-960
80x=24000+960
80x=24960
x=24960/80
x=312
12
*
  80

960
3)x/26+1654=2610
x/26=2610-1654
x/26=956       |*26
x=956*26
x=24856
 2610
-
 1654

   956