реши уравнение
5*(810/9-b*3)= 40*8-5

5·(810:9-b·3)=40·8-55·(90-3b)=320-5450-15b=31515b=450-31515b=135b=135:15b=95·(810:9-3·9)=40·8-55·(90-27)=320-55·63=315315=315

5*(810:9-b*3)=320-55*(810:9-b*3)=315(810:9-b*3)=315:5(810:9-b*3)=6390-b*3=63b*3=90-63b*3=27b=27:3b=9