用结合法,先把后面的减号提取出来,先算3/5+2/5的和,再用12减去它们的和。即:
12-3/5-2/5
=12-(3/5+2/5)
=12-1
=11
12-3/5-2/5简便算法怎么解?12-3/5-2/5
简便算法:
12-3/5-2/5
=12-(3/5+2/5)
=12-1
=11
解,原式=12-(3/5+2/5)
=12-1
=11
原式=12-(3/5+2/5)
=12-1
=11
1.给3/5-2/5加上拾号,因为3/5前是-号,所以3/5-2/5转为3/5+2/5
2.那么我们运用减法性质简便运算
12-3/5-2/5
=12-(3/5+25)
=12-1
=11