Perform the operation and reduce the answer fully. 1/10 + 2/9 =

You need to ensure the denominators are the same. To do this you multiply the denominators together.

1/90 + 2/90

However, this is incorrect, as you need to do the same to the numerators, so for the left hand side you multiplied by 9 and for the right hand side you multiplied by 10, so you must do the same for the numerators.

So it should be:

9/90 + 20/90

You can now add this together, to get:

29/90

This is triple checked so I'm not sure why it says reduce the answer fully as that is as far as it can be reduced.