So I'm playing around with some maths, looking through my old algebra and calculus books and came upon this problem and so, I went through and simplified it or at least I believe I've simplified it correctly.
Simplify $-8x - 12 + 3x - 5x + 9$
[(-8x - 12) + 3x] - 5x + 9 order of operations
[-8x - (12 + 3x)] - 5x + 9 associative property
at [... - (12 + 3x)], i think this is identity property
[-8x - (3x + 12)] - 5x + 9 commutative property
[-8x - 3x - 12] - 5x + 9
-11x - 12 - 5x + 9 combine like terms
[(-11x - 12) - 5x] + 9 order of operations
[-11x - (12 - 5x)] + 9 associative property
[-11x - (-5x + 12)] + 9 commutative property
-11x + 5x - 12 + 9
-6x - 12 + 9 combine like terms
-6x - 3 add
Is this the simplified answer -6x - 3 ?
Thanks,