Question

1+2+3+4+5+6+7+8+9

Answer 1

   1 + 2 +3 + 4 + 5 + 6 + 7 + 8 + 9 
= (1 + 9 ) + (2 + 8 ) + ( 3 + 7 ) + ( 4 + 6 ) + 5
= 10 + 10 + 10 + 10 + 5
= 45

Answer 2

=45

Answer 3

 1 + 2 +3 + 4 + 5 + 6 + 7 + 8 + 9 
= (1 + 9 ) + (2 + 8 ) + ( 3 + 7 ) + ( 4 + 6 ) + 5
= 10 + 10 + 10 + 10 + 5
= 45 đó nha

Answer 4

bằng 45

Answer 5

1+2+3+4+5+6+7+8+9=

(1+9)+(2+8)+(3+7)+(4+6)+5

=10+10+10+10+5=45

Answer 6

1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9

(1 + 9 ) + (2 + 8) + (3 + 7) + (4 + 6) + 5

10 + 10 + 10 + 10 + 5

20 + 20 + 5

40 + 5

45

Answer 7

45 nha bạn

Answer 8

45