11 + 22 + 33 + 44 + 55 + 66 + 77 + 88 + 99

= (11 + 88) + (22 + 77) + (33 + 66) + (44 + 55)  + 99

 =      99       +       99      +      99        +      99       + 99

= 99 x 5

= 495

11 + 22 + 33 + 44 + 55 + 66 + 77 + 88 + 99

= (11 + 99) + (22 + 88) + (33 + 77) + (44 + 66) + 55

=      110     +      110     +     110      +     110      + 55

= 495

11 + 22 + 33 + 44 + 55 + 66 + 77 + 88 + 99

= (11 + 99) + (22 + 88) + (33 + 77) + (44 + 66) + 55

= 110 +  110 +110 + 110 + 55

= 495

Tính bằng cách thuận tiện nhất:

                    11 + 22 + 33 + 44 + 55 + 66 + 77 + 88 + 99

                   = (11 + 88) + (22 + 77) + (33 + 66) + (44 + 55)  + 99

                   =      99       +       99      +      99        +      99       + 99

                   = 99 x 5

                   = 495

( 11 + 88 ) + ( 22 + 77 ) + ( 33 + 66 ) + ( 44 + 55 ) + 99 

= 99 + 99 + 99 + 99 + 99 

= 99 x 5 

= 495

( 11 + 99 ) + ( 22 + 88 ) + ( 33 + 77 ) + ( 44 + 66 ) + 55

= 100 + 100 + 100 + 100 + 55

= 450

11 + 22 + 33 + 44 + 55 + 66 + 77 + 88 + 99

= ( 11 + 99 ) + ( 22 + 88 ) + ( 33 + 77 ) + ( 44 + 66 ) + 55

= 110 + 110 + 110 + 110 + 55

= ( 110 x 4 ) + 55

= 440 + 55

= 495.

\(11+22+33+44+55+66+77+88+99\)

\(=\left(11+99\right)+\left(22+88\right)+\left(33+77\right)+\left(44+66\right)+55\)

\(=110+110+110+110+55\)

\(=550+55\)

\(=605\)

# Kukad'z Lee'z

= ( 99+11) +( 88+22)+...+(44+66)+55

= 110 +110+...+110+55

=440 +55 = 495

= 11(1+2+3+4+5+6+7+8+9) = 11 * 9(9+1) = 11*9*10 = 990

11 + 22 + 33 + 44 + 55 + 66 + 77 + 88 + 99

= (11 + 99) + (22 + 88) + (33 + 77) + (44 + 66) + 55

= 110 + 110 + 110 + 110 + 55

= 110 x 4 + 55

= 440 + 55

= 495 

11+22+33+44+55+66+77+88+99

=(11+99)+(22+88)+(33+77)+(44+66)+55

=110+110+110+110+55

=110x4+55

=440+55

=495

=(11+99)+(22+88)+(33+77)+(44+66)+55

=100+100+100+100+55

=400+55

=455

=(11+99)+(22+88)+(33+77)+(44+66)+55

=100+100+100+100+55

=400+55

=455

Hình như các bn làm sai rồi

[11 + 99] + [22 + 88] + [33 + 77] + [44 + 66]

= 110 + 110 + 110 + 110 

=110 x 4

=440

mình nghĩ là như z

= 1 + 11 + 11 + 11 + 11 = 1 + 4 . 11 = 1 + 44 = 45 

\(100-99+88-77+66-55+44-33+22-11\\ =\left(100-99\right)+\left(88-77\right)+\left(66-55\right)+\left(44-33\right)+\left(22-11\right)\\ =1+11+11+11+11\\ =1+11\times4\\ =1+44\\ =45\)

\(100-99+88-77+66-55+44-33+22-11\)

\(=1+11+11+11+11\)

=45