Tính. 1/2 - 1/4

a) $\frac{1}{2}$ - $\frac{1}{4}$

b) $\frac{2}{3}$ - $\frac{4}{15}$

c) $\frac{3}{5}$ - $\frac{10}{25}$

a) $\frac{1}{2}$ - $\frac{1}{4}$ = $\frac{2}{4}$ - $\frac{1}{4}$ = $\frac{1}{4}$

b) $\frac{2}{3}$ - $\frac{4}{15}$ = $\frac{10}{15}$ - $\frac{4}{15}$ = $\frac{6}{15}$= $\frac{2}{5}$

c) $\frac{3}{5}$ - $\frac{10}{25}$ = $\frac{15}{25}$ - $\frac{10}{25}$ = $\frac{5}{25}$ = $\frac{1}{5}$