10 would be the answer I believe.
What is the question. Is it asking for a picture of a line. Is it making a statement? Asking for a slope?
We have 5x-9 = Y= 2x+6
⇒ 5x-9 = 2x+6
⇒ (5x-2x)+ (-9+9) = (2x-2x)+ (6+9)
⇒ 3x= 15
⇒ x=5
Plug x=5 in Y = 5x-9, we have Y= 5*(5)-9
⇒ Y=16
(x,Y)= (5,16)
Hope this would help :))