It is answer choice B. Using the distributive property, -12x^3+15x^2-24x-6x^2+30x-42. Then combine like terms.
C. 2+3 = 5
1/12+1/12=2/12
So C would make sense because those all add up to the answer :-)
Answer: 
Step-by-step explanation:
We can rewrite the left hand side as a perfect square, more specifically

So, taking the square root of both sides,

I'm not so sure but from what I know the answer is option 2