We need to factor:
[tex]20k+50[/tex]There is not "k" factor that is common in both the terms.
But we can take out a factor of "10" from both terms, as common.
Thus,
[tex]\begin{gathered} 20k+50 \\ =10(\frac{20k}{10}+\frac{50}{10}) \\ =10(2k+5) \end{gathered}[/tex]Fully factorized form:
[tex]10(2k+5)[/tex]