It's easy. Your probably making it hard than it really is. If it helps you could possibly draw a picture with it to.
1) Multiply the numerators (18 and 7) to get 126. Multiply the denominators (1 and 9) to get 9.
2) So now you have reduced the the fraction to 126/9
3) Simplify it. 9 goes into 126, 13 times
So in the end your answer should be 13
Easy!!!!!!