Question

用递等式计算，能简算的要简算．1.25×3.2×0.25 &...

用递等式计算，能简算的要简算．1.25×3.2×0.25 7.5×1.013.6×4.6+5.4×3.6 8.7-4.7×1.412×0.25+8.8×2.5 4.04×25

Answer 1

（1）1.25×3.2×0.25
=1.25×（8×0.4）×0.25
=（1.25×8）×（0.4×0.25）
=10×0.1
=1；

（2）7.5×1.01
=7.5×（1+0.01）
=7.5×1+7.5×0.01
=7.5+0.075
=7.575；

（3）3.6×4.6+5.4×3.6
=3.6×（4.6+5.4）
=3.6×10
=36；

（4）8.7-4.7×1.4
=8.7-6.58
=2.12；

（5）12×0.25+8.8×2.5 
=12×0.25+88×0.25 
=（12+88）×0.25
=100×0.25
=25；

（6）4.04×25
=（4+0.04）×25
=4×25+0.04×25
=100+1
=101．