lasol
幼苗
共回答了21个问题采纳率:85.7% 举报
1、7/13÷7+1/7×6/13
=7/13×1/7+1/7×6/13
=﹙7/13+6/13﹚×1/7
=1×1/7=1/7
2、1/2×2/5+9/10÷9/20
=1/5+9/10×20/9
=1/5+2
=2又1/5
3、﹙1/2+2/3+3/4﹚×24
=1/2×24+2/3×24+3/4×24
=12+16+18
=12+18+16
=30+16
=46
4、7又1/3÷[ 1又1/4÷﹙4又2/3-1/2﹚]
=22/3÷[ 5/4÷﹙4+4/6-3/6﹚]
=22/3÷[ 5/4÷25/6]
=22/3÷﹙5/4×6/25﹚
=22/3÷3/10=220/9
5、2/9+1/2÷4/5+3/8
=2/9+5/8+3/8
=2/9+1
=1又2/9
1年前
2