You have an expression
That expression does not equal anyting (at least not anything we know).
So I supposed you are to break out n.
But you substitute for 36.
So that is only valid if n = 180?
But also the expression gains one = sign meaning it is now an equation. From the second row you have these, what is the operator between them?
Im sorry I have no idea if what you have done is correct. If it is an equation and not an expression you can just pop you final values into the equation and se if it is correct.
Remember if you have an expression like x^2+3x+4 you cantīautomatically assume that that equals zero and then solve for x.
Post exactly what you want me to check...