3.9*14.7-3.9*4.7 1.25*3.2*2.5 3.2*101怎样算简便就怎样算
问题描述:
3.9*14.7-3.9*4.7 1.25*3.2*2.5 3.2*101怎样算简便就怎样算
答
3.9*14.7-3.9*4.7
=3.9X(14.7-4.7)
=3.9X10
=39
1.25*3.2*2.5
=1.25X(8X0.4)X2.5
=(1.25X8)X(0.4X2.5)
=10X1
=10
3.2*101
=3.2X(100+1)
=3.2X100+3.2X1
=320+3.2
=323.2
望采纳