Answer:
C. 
Step-by-step explanation:
To find the value f b, we need to compare the exponents.
The given exponential equation is:

Recall and apply the following rule of exponents.

We apply this rule on both sides to get:

Simplify the exponents on the left.

Comparing exponents of the same variables on both sides,


Divide both sides by 6.


Group up the like terms and combine them
2x^2 and -7x^2 add up to -5x^2
6x and 2x add up to 8x
1 and -3 add up to -2
We end up with -5x^2 + 8x - 2
<h3>Answer: Choice B</h3>
I think the first one (hope it helps.