Question

tinh nhanh 1+2+5+9+14

Answer 1

1 + 2 + 5 + 9 + 14

= { 1 + 9 } + { 2 + 5 } + 14

= 10 + 7 + 14

 = 17 + 14

= 31

Answer 2

1 + 2 + 5 + 9 + 14= 1 + ( 2 + 14 ) + ( 5 + 9 )

​= 1 + 16 + 14​

​= 1 + 30

​= 31

Answer 3

1+2+5+9+14

=(1+5+14)+(2+9)

=20+11

=31

Answer 4

=(1+9)+(14+5)+2

=10+29+2

=41

Answer 5

1 + 2 + 5 + 9 + 14

= ( 1 + 14 ) + ( 2 + 9 ) + 5

= 15 + 11 + 5 

= ( 15 + 5 ) + 11

= 20 + 11

= 31

 

Answer 6

31

Khuê đây tick nha

Answer 7

tự làm di 

de ma

 

Answer 8

1 + 2 + 5 + 9 + 14

= ( 1+ 9 ) + ( 2 + 5 + 14)

=    10   +    21

= 31