You would just add all the numbers up, and by making sure that you combine all like terms. In this case it is just 1-0 = 1 and so the solution would be the same as your question but with a 1 and you would get rid of the -0.
First convert the equation to y=mx+b form you’ll get y=5/6x+27 then to find the line perpendicular to this equation, you have the flip the slope. ending with -6/5
