Question

用递等式计算（怎样简便就怎样计算）．5.6×0.85×7.8 4.32×99+4.32 99×3.74...

用递等式计算（怎样简便就怎样计算）．5.6×0.85×7.8 4.32×99+4.32 99×3.74 1.25×3.2×0.25 1.2×2.6+3×4.25 1.25×7.2．

Answer 1

（1）5.6×0.85×7.8
=4.76×7.8
=37.128；

（2）4.32×99+4.32
=4.32×（99+1）
=4.32×100
=432；

（3）99×3.74
=（100-1）×3.74
=100×3.74-3.74
=374-3.74
=370.6；

（4）1.25×3.2×0.25
=1.25×8×0.4×0.25
=（1.25×8）×（0.4×0.25）
=10×0.1
=1；

（5）1.2×2.6+3×4.25    
=33.12+12.75
=45.87；

（6）1.25×7.2
=1.25×8×0.9
=（1.25×8）×0.9
=10×0.9
=9．