如题所述
第1个回答 2016-05-12
2/7+1/5-1/7
=2/7-1/7+2/5
=1/7+2/5
=19/35
3.14×2.3+3.14×3.7
=3.14×（2.3+3.7）
=3.14×6
=18.84
12.5×（6.1+0.26）×8
=（12.5×8）×6.36
=100×6.36
=636
14/15×1/4+1/15÷4
=14/15×1/4+1/15×1/4
=（14/15+1/15）×1/4
=1×1/4
=1/4
930÷[1/2×（2/5+4/5）]
=930÷[1/2×6/5]
=930÷3/5
=1550
3又2/5×99+3.4
=3.4×99+3.4
=3.4×（99+1）
=3.4×100
=340
=2/7-1/7+2/5
=1/7+2/5
=19/35
3.14×2.3+3.14×3.7
=3.14×（2.3+3.7）
=3.14×6
=18.84
12.5×（6.1+0.26）×8
=（12.5×8）×6.36
=100×6.36
=636
14/15×1/4+1/15÷4
=14/15×1/4+1/15×1/4
=（14/15+1/15）×1/4
=1×1/4
=1/4
930÷[1/2×（2/5+4/5）]
=930÷[1/2×6/5]
=930÷3/5
=1550
3又2/5×99+3.4
=3.4×99+3.4
=3.4×（99+1）
=3.4×100
=340
第2个回答 2016-05-12
追答
详细步骤写在纸上了
望采纳，谢谢
本回答被提问者采纳第3个回答 2016-05-12
第4个回答 2016-05-12
第5个回答 2016-05-12
追答
