Question

用递等式计算（能简算的要简便计算）．（1）25.5-8.64-1.36；（2）4.5÷1.25×8；（3）1.25×32×0.25；

用递等式计算（能简算的要简便计算）．（1）25.5-8.64-1.36；（2）4.5÷1.25×8；（3）1.25×32×0.25；（4）0.18×4.25-0.18+6.75×0.18；（5）（3.6×1.75-3.6÷4）÷0.09；（6）0.1×[0.5+1÷（7.5-7.46）]．

Answer 1

（1）25.5-8.64-1.36
=25.5-（8.64+1.36）
=25.5-10
=15.5

（2）4.5÷1.25×8
=3.6×8
=28.8

（3）1.25×32×0.25
=1.25×8×4×0.25
=（1.25×8）×（4×0.25）
=10×1
=10

（4）0.18×4.25-0.18+6.75×0.18
=0.18×（4.25-1+6.75）
=0.18×10
=1.8

（5）（3.6×1.75-3.6÷4）÷0.09
=（6.3-0.9）÷0.09
=5.4÷0.09
=60

（6）0.1×[0.5+1÷（7.5-7.46）]
=0.1×[0.5+1÷0.04]
=0.1×[0.5+25]
=0.1×0.5+0.1×25
=0.05+2.5
=2.55