Question

 

1+2+3+4+5+6+7+8+9+99999999999=???

 

Answer 1

1+2+3+4+5+6+7+8+9+99999999999=100000000044

Answer 2

ta có: 1+...+9

= \(\left(\frac{9-1}{1}+1\right)\left(\frac{9+1}{2}\right)\)

=9 x 5 =45

=> 1+2+3+4+5+6+7+8+9+99999999999=45+99999999999=100000000044

Answer 3

= 100000000044

Answer 4

100000000044 nha