Answer:
a. incorrect, the first step would have been to distribute the 2.
b. incorrect, it would be, -12x +x + 9-8 +5
c. correct, the distribution is correct
Explanation:
Just remember PEMDAS.
Perentheses, Exponents, Multipication, Division, Addition, Subtraction
i really hope this helps, i'm sorry if it isn't correct