Hello,
we are going to use the theorem of the bissectrice. (if this word is good in english)
[tex]\dfrac{KL}{LM} =\dfrac{KN}{NM} \\\\\dfrac{8}{x} =\dfrac{14}{20-x} \\\\8(20-x)=14x\\\\160-8x=14x\\\\22x=160\\\\x=\frac{160}{22} \\\\x=\frac{80}{11} \\\\\\x=7.\overline{27}[/tex]
