This question was uploaded on 16/11/21 on social media accounts.
Solution:
Due to the angle bisector and median together, the triangle is an isosceles triangle.
Angle bisector theorem on point M:
\[\frac{4x+4x}{c+5x}=\frac{5x}{c}\]
\[\Rightarrow c=\frac{25x}3\]
\[\Rightarrow \frac bc = \frac35\]
