I also think its 4 but im not sure
Answer:

Step-by-step explanation:
The only thing important in this question in the original equation is the slope, which is 3, the multiplyer for x. To find the opposite slope follow the steps below.
The first step is to make the original slope into a fraction.

Then flip the numerator and denominator.

Now multiply this value by -1.

There is the opposite slope of 3.
Answer:
3 is not a like term because it isn't an x term, it doesn't have an x variable while the other terms do.