Hi I’ve been struggling with 19 and 20 for sometime now

Given:
[tex]HK=x-5,KJ=5x-12,HJ=25[/tex]K is between the points H and J.
[tex]HJ=HK+KJ[/tex][tex]25=x-5+5x-12[/tex][tex]25=6x-17[/tex][tex]25+17=6x[/tex][tex]42=6x[/tex][tex]x=\frac{42}{6}[/tex][tex]x=7[/tex]