Respuesta :
The diagram of the given question is attached .
Since line segment QC parallel to BR, so the two triangles are similar .
And when triangles are similar, the corresponding sides are in same proportion. That is
[tex] \frac{DQ}{QB} = \frac{DC}{CR}
\\
\frac{39}{26} = \frac{x}{18} [/tex]
On performing cross multiplication , we will get
[tex] 39*18 = 26x
\\
x = \frac{39*18}{26} = 27 [/tex]
