Breuken haakjesregel (reeks 1)

Bereken

\(-\left(\frac{-4}{-3}\right)-\left(\frac{-4}{-7}\right)\)

\(-\left(\frac{-4}{-3}\right)-\left(\frac{-4}{-7}\right)\\= \frac{-4}{3}-\frac{4}{7}\\=\frac{-28}{21}-\frac{12}{21}\\=\frac{-28-12}{21}\\=\frac{-40}{21}\)