简便运算 7.4乘9.8减14.5

问题描述:

简便运算 7.4乘9.8减14.5

7.4*9.8-14.5
=7.4*(10-0.2)-14.5
=74-1.48-14.5
=58.02

1051.54

原式=7.4*(10-0.2)-14.5
=74-1.48-14.5
=74-15.98
=58.02

=7.4×(100-2)-14.5
=7.4×100-7.4×2-14.5
=740-14.8-14.5
=740-29.3
=710.7