如题所述
① 7/25×101-7/25
=7/25×(101-1)
=7/25×100
=28
②（5/6+7/8-5/12）÷1/2
=(5/6+7/8-5/12)×2
=5/6×2+7/8×2-5/12×2
=5/3-5/6+7/4
=5/6+7/4
=10/12+21/12
=31/12
③ 75%×3/7+1/7×3/4+3/7×0.75
=0.75×（3/7+1/7+3/7）
=0.75×1
=0.75
不懂可追问，有帮助请采纳，谢谢！追问
=7/25×(101-1)
=7/25×100
=28
②（5/6+7/8-5/12）÷1/2
=(5/6+7/8-5/12)×2
=5/6×2+7/8×2-5/12×2
=5/3-5/6+7/4
=5/6+7/4
=10/12+21/12
=31/12
③ 75%×3/7+1/7×3/4+3/7×0.75
=0.75×（3/7+1/7+3/7）
=0.75×1
=0.75
不懂可追问，有帮助请采纳，谢谢！追问
弄错了！
②（5/6+7/8-5/12）÷1/24
=
温馨提示：答案为网友推荐，仅供参考
第1个回答 2013-01-10
① 7/25×101-7/25=7/25×(100+1)-7/25
=28+7/25-7/25
=28
②（5/6+7/8-5/12）÷1/2=（5/6+7/8-5/12）x2
=5/3+7/4-5/6
=5/6+7/4
=10/12+21/12
=31/12
③ 75%×3/7+1/7×3/4+3/7×0.75=3/4x3/7+1/7x3/4+3/7x3/4
=3/4x(3/7+1/7+3/7)
=3/4x1
=3/4
愿你学习进步
=28+7/25-7/25
=28
②（5/6+7/8-5/12）÷1/2=（5/6+7/8-5/12）x2
=5/3+7/4-5/6
=5/6+7/4
=10/12+21/12
=31/12
③ 75%×3/7+1/7×3/4+3/7×0.75=3/4x3/7+1/7x3/4+3/7x3/4
=3/4x(3/7+1/7+3/7)
=3/4x1
=3/4
愿你学习进步
第2个回答 2013-01-10
都是结合律和分配率的应用吧
