Question

六年级数学简便运算;1/13*39*8/21 7/8/9*3/5/35/72 （1/15+3/49）*15-45/49 （7/10+5/6+4/5）

Answer 1

1/13*39*8/21
=1/3×8/21
=8/63

7/8/9*3/5/35/72
=7/72×3/5×72/35
=3/25

（1/15+3/49）*15-45/49
=1+45/49-45/49
=1

（7/10+5/6+4/5）
=7/10+8/10+5/6
=15/10+5/6
=3/2+5/6
=14/6
=7/3

追问

3/5*153-0.6*53 8/9{3/5-（9/16-2/5）} 17/24*1/5+7/24/5+1/5

追答

3/5*153-0.6*53
=0.6×153-0.6×53
=0.6×(153-53)
==0.6×100
=60

8/9{3/5-（9/16-2/5）}
=8/9×(3/5-9/16+2/5)
=8/9×(1-9/16)
=8/9×7/16
=7/18

17/24*1/5+7/24/5+1/5
=17/24*1/5+7/24*1/5+1/5
=1/5*(17/24+7/24+1)
=1/5*2
=2/5

Answer 2

什么 中间没隔开？没看懂