Karim occasionally cycles the 24km journey to school. When he hurries and increases his normal average speed, v, by 6km/h his journey time is cut by 40 minutes. How long does it normally take him to cycle to school?
Perhaps coding it will make things a bit clearer:
$\displaystyle \left ( 6 + \frac{24}{t} \right ) \left ( t - \frac{2}{3} \right )$
$\displaystyle 6 \cdot t + 6 \dot -\frac{2}{3} + \frac{24}{t} \cdot t + \frac{24}{t} \cdot - \frac{2}{3}$
Can you see how to do this step now, and can you continue?
-Dan