Question

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

NHỚ GHI CÁCH GIẢI NHÉ

Answer 1

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

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

= 2 x 45

= 90

Answer 2

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

=2*45

=90

           k mình nha !!!

Answer 3

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

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

= 2 x 45

= 90

Answer 4

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

=       2x(1+2+3+4+5+6+7+8+9)

=              2x45

=                 90

Answer 5

ỏi tui chịu lun

Answer 6

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

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

=2 x 45

=90