(3/8+4/5-7/10)×40

问题描述:

(3/8+4/5-7/10)×40

(3/8+4/5-7/10)×40
=3/8×40+4/5×40-7/10×40
=3×5+4×8-7×4
=15+32-28
=19
利用的是乘法分配律

=3/8×40+4/5×40-7/10×40
=15+32-28
=19

(3/8+4/5-7/10)×40
=3/8×40+4/5×40-7/10×40
=15+32-28
=19