Answer:
11/12 = 55/60, 9/10 = 54/60
Explanation:
First, find what the common denominator would be. To do this, you want to find the LCM of 12 and 10, or the smallest possible number that is divisible by both 12 and 10.
This would be 60.
Next, you want to make the denominator 60.
You can do: 11/12 * 5/5 = 55/60
And: 9/10 * 6/6 = 54/60