Answer: Yes, it is.
First you have to subtract X on both sides.
9x-9x+11y=-9x+15
equals
11y=-9x+15 (You cannot combine unlike numbers)
You divide both sides by 11.
11y/11= -9x+15/11
equals
Y= -9/11 X+15/11
Although it doesn't look so, graphing calculators online will show that this answer in linear.