First let's find the value of the interior angle of the traingle at point Y.
The angles form a straight angle (180 degrees)
115+x=180
x= 65
All three interior angles of a triangle must add to 180 degrees.
65+ (6k+10)+(4k+5)=180
Combine like terms
80+10k=180
Subtract 80 from both sides
10k=100
Divide both sides by 10
k=10
Final answer: k=10