用竖式计算，能简算的要简算．43.6-17.8+6.4-12.212.5×0.25×3.2（18.5+27.83÷4.6）×0.22.31×2.5+2.5×7.696.5×985.25÷[（1.2+0.05）×1.4]

Question

用竖式计算，能简算的要简算．

43.6-17.8+6.4-12.2	12.5×0.25×3.2	（18.5+27.83÷4.6）×0.2
2.31×2.5+2.5×7.69	6.5×98	5.25÷[（1.2+0.05）×1.4]

Answer 1

（1）43.6-17.8+6.4-12.2 
=（43.6+6.4）-（17.8+12.2）
=50-30
=20

（2）12.5×0.25×3.2 
=12.5×0.25×4×0.8
=（12.5×0.8）×（0.25×4）
=10×1
=10

（3）（18.5+27.83÷4.6）×0.2
=（18.5+6.05）×0.2
=24.55×0.2
=4.91

（4）2.31×2.5+2.5×7.69
=2.5×（2.31+7.69）
=2.5×10
=25

（5）6.5×98
=6.5×（100-2）
=6.5×100-6.5×2
=650-13
=637

（6）5.25÷[（1.2+0.05）×1.4]
=5.25÷[1.25×1.4]
=5.25÷1.75
=3