2.4x[2.5/7.5] 2.5x2.4x2.5

问题描述:

2.4x[2.5/7.5] 2.5x2.4x2.5

2.4x[2.5/7.5]
=2.4x1/3
=0.8
2.5x2.4x2.5
=2.5x4x2x0.3x2.5
=10x0.3x2x2.5
=3x5
=15