Question

1+2+3+4+5+6+7+8+9+10 = ???

Answer 1

1+2+3+4+5+6+7+8+9+10

=(1+10):2x10

=11:2x10

=55

Answer 2

55

k cho mk nha

mk nhanh nhất

Answer 3

1+2+3+4+5+6+7+8+9+10

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

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

=55

Answer 4

1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10
Cách 1:
1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10
= 3 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10
= 6 + 4 + 5 + 6 + 7 + 8 + 9 + 10
= 10 + 5 + 6 + 7 + 8 + 9 + 10
= 15 + 6 + 7 + 8 + 9 + 10
= 21 + 7 + 8 + 9 + 10
= 28 + 8 + 9 + 10
= 36 + 9 + 10
= 45 + 10
= 55

Cách 2:
1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10
= ( 1 + 9 ) + ( 2 + 8 ) + ( 3 + 7 ) + ( 4 + 6 ) + 5 + 10
= 10 + 10 + 10 + 10 + 5 + 10
= 10 . 5 + 5
= ( 10 . 5 ) + 5
= 50 + 5
= 55

Answer 5

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

10+10+10+10+15

55