(2400+z)/40=80,1500/x-300=200,2800-(t-357)=100
1)2400+Z=40*80
2400+z=3200
z=3200-2400
z=800
2)1500\x=200+300
1500\x=500
x=1500\500
x=3
3)-(t-357)=100-2800
-(t-357)=-2700
t-357=2700
t=2700+357
t=3057