all the fractions that you are subtracting have the same denominator so you just subtract the numerator.2/5-1/5=1/5
3/8-2/8=1/8
79-3/9 since you can simplify 3/9 by 3 you get 1/3 you get 79/1-1/3.the common denominator is 3 so you multiply 79/1 by 3 and 1/3 by 1 and then you get 237/3-1/3 and you get 236/3. then you turn it from an improper fraction into a mixed number. 236 divided by and you get 78.6 repeating
