简算:79.8×80.2=?

分类: 作业答案 • 2021-12-19 17:38:49

问题描述：

简算:79.8×80.2=?

答

79.8×80.2
=（80-0.2）×（80+0.2）
=80²-0.2²
=6400-0.04
=6399.96

答

=(80-0.2)(80+0.2)
=80^2 - 0.2^2
=6400 - 0.04
= 6399.96

答

79.8×80.2
=(80-0.2)(80+0.2)
=80^2-0.2^2
=6400-0.04
=6399.96