Y+30×5=540 ,b-70×3=345, c+4×25=985, a÷(400-360)=8,b×(300-250)=550, 45÷5×b=900

Y+30×5=540 ,
y+150=540
y=540-150
y=390

b-70×3=345,
b-210=345
b=345+210
b=555

 c+4×25=985,
c+100=985
c=985-100
c=885

a÷(400-360)=8,
а:40=8
а=8*40
а=320

b×(300-250)=550,
50b=550
b=550:50
b=11

 45÷5×b=900
45:5b=900
900*5b=45
4500b=45
b=45:4500
b=0.01