Answer: 
 yard.
 yard.
Explanation:
 You have the following information given in the problem:
 - You have 3/4 yard of felt.
 - You used 1/8 yard,
 Therefore, to find the fraction of a yard of felt that you have left over (which you can call x), you only need to subtract 3/4yard and 1/8 yard, as you can see below:
 
