用递等式计算,能简算的要写出简算过程. 42÷[14-(50-39)] 7.25×1.8+27.5×0.18 905×99+905.

问题描述:

用递等式计算,能简算的要写出简算过程.
42÷[14-(50-39)]
7.25×1.8+27.5×0.18
905×99+905.


42÷[14-(50-39)]
=42÷(14-11)
=42÷3
=14;
7.25×1.8+27.5×0.18
=7.25×1.8+2.75×1.8
=1.8×(7.25+2.75)
=1.8×10
=18;
905×99+905
=905×99+905×1
=905×(99+1)
=905×100
=90500.
故答案为:17;18;90500.