1.9-0.4×1.9-0.6×1.9+1.9简便计算

问题描述:

1.9-0.4×1.9-0.6×1.9+1.9简便计算

1.9-0.4×1.9-0.6×1.9+1.9
=1·9×(1-0·4-0·6+1)
=1·9×(2-1)
=1·9