You’re finding the least common denominator do you have to find what number the denominators can go into evenly. For example number one: 4 and 6 go into 12
1/4, multiply both top and bottom by 3. That will give you 3/12
Now te same for 5/6. Now multiply both top and bottom by 2 and the equals 10/12
Final answer 3/12, 10/12. If you need more help just comment! :)