You can put this solution on YOUR website! I think it means that 171/9 can be written as
(1) (1/9)(90 + 81)
which simplifies using multiplicative distribution to
(2) (1/9)*90 + (1/9)*81
which reduces to
(3) 10 + 9 = 19
This is a good example of a senseless question. Have a good night.