1.345*0.345*2.69-1.345*1.345*1.345-1.345*0.345*0.345
问题描述：
1.345*0.345*2.69-1.345*1.345*1.345-1.345*0.345*0.345
答
=1.345*0.345*(2.69-0.345)-1.345*1.345*1.345
=1.345*0.345*2.345-1.345*1.345*1.345
=1.345*[(1.345-1)(1.345+1)-1.345*1.345]
=1.345*(-1)
=-1.345