Question

tính nhanh : 1-2+3-4+5-6+7-8+9 

cứu

Answer 1

=(-1)+(-1)+(-1)+(-1)+9=9-4=5

Answer 2

1 - 2 + 3 - 4 + 5 - 6 + 7 - 8 + 9 

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

= 1 + 1 + 1 + 1 + 1

= 5

Answer 3

= 5

 

Answer 4

5

Answer 5

5

Answer 6

\(=5\)

Answer 7

Bằng 5

Answer 8

1 - 2 + 3 - 4 + 5 - 6 + 7 - 8 + 9 

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

= 1 + 1 + 1 + 1 + 1

= 5

Answer 9

1 - 2 + 3 - 4 + 5 - 6 + 7 - 8 + 9 

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

= 1 + 1 + 1 + 1 + 1

= 5

Answer 10

= 5

Answer 11

5

Answer 12

5

Answer 13

= 5

Answer 14

5

Answer 15

5