Fraction Subtraction (Like Denominators)

Find the difference. Simplify all answers completely. Change improper fractions to mixed numbers. 

1.  $\dfrac{3}{5}$ -  $\dfrac{2}{5}$=

2.  $\dfrac{20}{40}$ -  $\dfrac{16}{40}$=

3.  $\dfrac{15}{18}$ -  $\dfrac{8}{18}$=

4.  $\dfrac{9}{16}$ -  $\dfrac{5}{16}$= 

5.  $\dfrac{21}{25}$ -  $\dfrac{18}{25}$=

6.  $\dfrac{9}{20}$ -  $\dfrac{8}{20}$=

7.  $\dfrac{7}{9}$ -  $\dfrac{2}{9}$=

8.  $\dfrac{43}{50}$ -  $\dfrac{9}{50}$=

9.  $\dfrac{13}{15}$ -  $\dfrac{6}{15}$=

10. $\dfrac{7}{9}$ -  $\dfrac{2}{9}$=

11.  $\dfrac{8}{10}$ -  $\dfrac{5}{10}$=

12.  $\dfrac{15}{20}$ -  $\dfrac{11}{20}$=