Hello!
A mixed number is a combination of an integer and a fraction. For example, 1 1/2 is a mixed number. An improper fraction is where the numerator is greater than the denominator. For example, 3/2.
To write a mixed number as the improper fraction, first convert the integer to be a fraction with the same denominator. I'm going to use the mixed number 5 2/3 as an example here.
5 2/3 = 15/3 + 2/3
Now, add together the two fractions.
15/3 + 2/3 = 17/3
And there you have your improper fraction.
Hope this helps!