Question

能简便则简算 1/5+1/2+2/3 5/4+9/13+1/5 2-5/12-7/12

9/7+1/6-2/7+5/6
13/15-（13/15-2/5）
7/12+（1/3-1/4）

Answer 1

=9/12+5/12 =7/6 3. 7/12-3/24*5*12/15 =7/12-1/2 =1/12 4. 6/7+3/4*6/5*2/7 =6/7+9/35 =39/35 5 （1/2-1/6）*5+1/4*4/5 =1/3*5+1/5 =28/15 6. 11/28*...

Answer 2

=9/12+5/12 =7/6 3. 7/12-3/24*5*12/15 =7/12-1/2 =1/12 4. 6/7+3/4*6/5*2/7 =6/7+9/35 =39/35 5 （1/2-1/6）*5+1/4*4/5 =1/3*5+1/5 =28/15 6. 11/28*...

Answer 3

1/5+1/2+2/3

=6/30+15/30+20/30
=41/30

5/4+9/13+1/5
=325/260+180/260+52/260
=557/260

2-5/12-7/12
=2-(5/12+7/12)
=2-1
=1

9/7+1/6-2/7+5/6
=(9/7-2/7)+(1/6+5/6)
=1+1
=2
13/15-（13/15-2/5）
=13/15-13/15+2/5
=0+2/5
=2/5
7/12+（1/3-1/4）
=7/12+1/12
=2/3

Answer 4

9/7+1/6-2/7+5/6=（9/7-2/7）+(1/6+5/6)=1+1=2
13/15-（13/15-2/5）=13/15-13/15+2/5=2/5
7/12+（1/3-1/4）=7/12+(4/12-3/12)=7/12+1/12=8/12=2/3

Answer 5

解：1/5+1/2+2/3=(6+15+20)/30
=41/30
5/4+9/13+1/5=(325+180+52)/
260=557/260
2-5/12-7/12=2-(5/12+7/12)
=2-12/12=2-1=1