We have two combined integer fractions, so let's take the integers first. 24-5=19. Now we can deal with the fractions. We need the lowest common denominator which in this case is 10*11=110. 1/10 is the same as 11/110 and 9/11 is the same as 90/110 (divide the denominator into 110 and multiply the numerator by the result). So we have 11/110-90/110 or (11-90)/110. But that's going to give us a negative number, therefore we need to borrow 1 (as 110/110) from the sum of the integers which, you remember was 19. So we have 18 and 110/110. Now we can do the arithmetic: (110+11-90)/110=31/110. Put the integer and fraction together and we have the complete answer: 18 and 31/110 (8 and 31 one-hundred-and-tenths).