简算 18.8-八份之二-3.8-三份之一简算 4.9×6.4+14×0.36-6.4×3.5
问题描述:
简算 18.8-八份之二-3.8-三份之一
简算 4.9×6.4+14×0.36-6.4×3.5
答
4.9×6.4+14×0.36-6.4×3.5
=4.9×6.4-6.4×3.5+14×0.36
=6.4×﹙4.9-3.5﹚+14×0.36
=6.4×1.4+14×0.36
=14×0.64+14×0.36
=14×﹙0.64+0.36﹚
=14×1=14
答
18.8-2/8-3.8-1/3=18.8-3.8-1/4-1/3=15-7/12=14又5/124.9×6.4+14×0.36-6.4×3.5=(4.9-3.5)×6.4+14×(1-0.64)=(4.9-3.5)×6.4+14-1.4×6.4=(4.9-3.5-1.4)×6.4+14=0+14=14