The next step is: 198 = 1 x 171 + 27. For each new step, you take the two rightmost numbers from the previous step.
Find the GCD for 198 and 765
I got as far as:
I'm not sure what to do for the next step.
Then I guess you didn't really learn the Euclidean Algorithm.
1. Divide the larger number by the smaller.
2. Divide the divisor by the remainder.
3. Repeat step 2 until a zero remainder is achieved.
4. The GCD is the last divisor.
So we have: