Why cant you add fractions with unlike denominator's?

You can't directly add fractions with unlike denominators because they represent different parts of a whole. To combine them, you first need to find a common denominator, which allows you to express each fraction in terms of the same whole. Once they have the same denominator, you can then add the numerators while keeping the common denominator. This ensures that the fractions accurately represent the same type of quantity before they are added.