Basically you make sure that both of the mixed fractions have the same denominator. Aka the common denominator, 4 goes into 8, so 8 is a common denominator. whatever you do the top you do to the bottom, so your new equation for 5 3/4 is 5 6/8. between 5 6/8 and 1 7/8 you figure out the difference. 5-1 = 4 so the difference between 7/8 and 6/8 is 1/8 so your answer is 4 1/8. hopefully i helped you :))
