Question

tính 1+2+3+17+18+19

Answer 1

60

Answer 2

= 60

Answer 3

 1+2+3+17+18+19

= ( 1+ 19 ) + ( 2 + 18 ) + ( 3 + 17 )

= 20 + 20 + 20

= 60

Answer 4

pằng 60 nhe~

Answer 5

60

Answer 6

 1+2+3+17+18+19

= ( 1+ 19 ) + ( 2 + 18 ) + ( 3 + 17 )

= 20 + 20 + 20

= 60

Answer 7

60

Answer 8

60

Answer 9

60