We need to subtract both expressions, then simplify it and make only one expression:
First, subtract both expressions:
[tex](-3x+9y)-(8x-6y)[/tex]Then:
[tex]-3x+9y-8x+6y[/tex]Now, simplify like terms:
[tex]-11x+15y[/tex]Therefore, the result expression is -11x+15y.