脱式计算（能简便要简便计算）

题目

脱式计算（能简便要简便计算）
3/4 ×8/13+5/13×3/4-3/4=
3/5+（5/8+3/8）÷5/6 =
(5/6-5/8)×24=
7/10÷(1-3/4×2/5)=
4/9×[3/4-(7/16-1/4)]=

答案

(1)3/4 ×8/13+5/13×3/4-3/4
=3/4 ×(8/13+5/13-1)
=3/4×(1-1)
=3/4×0
=0
(2)
3/5+（5/8+3/8）÷5/6
=3/5+1÷5/6
=3/5+1×6/5
=3/5+6/5
=9/5
(3)
(5/6-5/8)×24
=5/6×24-5/8×24
=20-15
=5
(4)
7/10÷(1-3/4×2/5)
=7/10÷(1-3/10)
=7/10÷7/10
=1
(5)
4/9×[3/4-(7/16-1/4)]
=4/9×(3/4+1/4-7/16)
=4/9×(1-7/16)
=4/9×9/16
=4/16
=1/4