0.42X9.9+0.042 12.5X(100+0.8) 12X0.75/2.5 简便运算怎么算?
问题描述:
0.42X9.9+0.042 12.5X(100+0.8) 12X0.75/2.5 简便运算怎么算?
答
0.42X9.9+0.042
=0.42×9.9+0.42×0.1
=0.42×(9.9+0.1)
=0.42×10
=4.2
12.5X(100+0.8)
=12.5×100+12.5×0.8
=1250+10
=1260
12X0.75/2.5
=12×(0.75/2.5)
=12×0.3
=0.36