Find the commomon denominator of 6 and 5.
It's 6 · 5 = 30.
[tex]\dfrac{5}{6}=\dfrac{5\cdot5}{6\cdot5}=\dfrac{25}{30}\\\\\dfrac{1}{5}=\dfrac{1\cdot6}{5\cdot6}=\dfrac{6}{30}[/tex]
[tex]\left(\dfrac{5}{6}-\dfrac{1}{5}\right)\div\dfrac{4}{5}=\left(\dfrac{25}{30}-\dfrac{6}{30}\right)\div\dfrac{4}{5}=\dfrac{25-6}{30}\div\dfrac{4}{5}=\dfrac{19}{30}\div\dfrac{4}{5}[/tex]
Divide by fraction is the same like multiply by reciprocal of this fraction:
[tex]=\dfrac{19}{30}\cdot\dfrac{5}{4}=\dfrac{19}{6}\cdot\dfrac{1}{4}=\dfrac{19}{24}[/tex]
