3.2×1.25×2.5 42.6÷2.5÷4 递等式（能简算要简算）

3.2×1.25×2.5
=8X0.4×1.25×2.5
=8×1.25X(0.4×2.5 )
=10 X 1
=10
42.6÷2.5÷4
=42.6 ÷(2.5X4)
=42.6 ÷10
=4.26
0.75×24÷0.25
=0.75÷0.25×24
=3 X24
=72