So you need to find common denominator
In the case it would be 12 so for 3/4 to get the denominator 212 you have to do times three so whatever you do to the party to the top so it would then be 9/12 then for 5/6 to get from 6 to 12 we have to do times two so would be 10/12 then you leave the other two numbers the same the eight and the five are fine so I like to do 8-5 first which equals three and then when you look at 9/12 -10/12 you can’t do that so it would be negative -1/12 then you bring over the other whole number leaving you with a final
Answer of. -3 1/12
I really hope this helped