如题所述
第1个回答 2021-05-04
15×142–140×14–142
=15×142–1×142–140×14
=(15–1)×142–140×14
=14×142–14×140
=14×(142–140)
=14×2
=28
=15×142–1×142–140×14
=(15–1)×142–140×14
=14×142–14×140
=14×(142–140)
=14×2
=28
第2个回答 2021-05-04
15×142-140×14-142=(14+1)×142-140×14-142=14×142+142-140×14-142=14×142-140×14+142-142=14×(142-140)+(142-142)=14×2+0=28
第3个回答 2021-05-04
原式=14x142-140×14,
=14×(140+2)-140×14,
=14×140+14×2-140×14,
=14×2,
=28
=14×(140+2)-140×14,
=14×140+14×2-140×14,
=14×2,
=28
第4个回答 2021-05-04
15×142-140×14-142
=142×(15-1)-140×14
=142×14-140×14
=14×(142-140)
=14×2
=28
=142×(15-1)-140×14
=142×14-140×14
=14×(142-140)
=14×2
=28
第5个回答 2021-05-04
=15*142-142-140*14=14*142-140^14=14*(142-140)=28