20 x 80 + 70 x 80 + 80 x 10
`20*80+70*80+80*10` `=` `80(20+70+10)` `=` `80*100` `=` `8000`
`#Quân
20.80+70.80+80.10
=80.[20+70+10]
=80.100
=8000
20 x 80 + 70 x 80 + 80 x 10=80x(20+70+10)=80x100=8000
`20*80+70*80+80*10` `=` `80(20+70+10)` `=` `80*100` `=` `8000`
`#Quân
20.80+70.80+80.10
=80.[20+70+10]
=80.100
=8000
20 x 80 + 70 x 80 + 80 x 10=80x(20+70+10)=80x100=8000