Answer:
[tex]x=4[/tex]
Step-by-step explanation:
[tex]\textsf{Mean basis Theorem;}[/tex]
[tex]\overline{JK}=2.\overline{NO}[/tex]
[tex]3x+26=2\times19[/tex]
[tex]3x=38-26[/tex]
[tex]3x=12[/tex]
[tex]x=12/3[/tex]
[tex]\boxed{x=4}[/tex]