Question

tính nhanh : 2/5 + 6/9 + 3/4 + 3/5 + 1/3 + 2/8

Answer 1

=(2/5+3/5)+(2/3+1/3)+(3/4+1/4)

=1+1+1=3

Answer 2

`2/5+6/9+3/4+3/5+1/3+2/8`

`=(2/5+3/5)+(6/9+1/3)+(3/4+2/8)`

`=5/5+(6/9+3/9)+(6/8+2/8)`

`=1+9/9+8/8=1+1+1=3`

Answer 3

2/5 + 6/9 + 3/4 + 3/5 + 1/3 + 2/8

= (2/5 + 3/5) + (6/9 + 1/3) + (3/4 + 2/8)

= 1 + 1 + 1

= 3

Answer 4

2/5 + 6/9 + 3/4 + 3/5 + 1/3 + 2/8

= ( 2/5+3/5 ) + ( 2/3+1/3 ) + ( 3/4+1/4 )

=1 + 1 + 1

= 3

Answer 5

2/5 + 6/9 + 3/4 + 3/5 + 1/3 + 2/8

=(2/5+3/5)+(2/3+1/3)+(3/4+1/4)

=1+1+1=3

Answer 6

= (2/5 + 3/5) + (6/9 + 1/3) + (3/4 + 2/8)

= 1  + 1 1

= 3

Answer 7

dui hè

Answer 8

3 nha bạn