In this module, you can how learn how to subtract one mixed number from another.
The video above from Khan Academy shows how to add two mixed numbers with common denominators.
The above video shows how to add mixed numbers with unlike denominators.
This video from Khan Academy shows you two ways to subtract mixed numbers.
You can change the number 3 into a fraction by putting it over 1. For example, you can change 3 into 3/1, and you can change -2 into -2/1.
Practice and study
Use this search term to find your own resources:
subtracting mixed numbers