Đáp án + Giải thích các bước giải:
`4.` `66*25+5*66+66*14+33*66`
`=66(25+5+14+33)`
`=66*77`
`=5082`
`5.` `12*35+35*182-35*94`
`=35(12+182-94)=35*100`
`=3500`
`6.`
`35*23+35*41+64*65`
`=35(23+41)+64*65`
`=35*64+64*65`
`=64(35+65)`
`=64*100=6400`
`7.`
`29*87-29*23+64*71`
`=29(87-23)+64*71`
`=29*64+64*71`
`=64(29+71)`
`=64*100=6400`.