The answer is C just guessed and i got it right.
Answer:
C. 4.2a + 0.8
Step-by-step explanation:
Given:
The two binomials given for addition are:
and 
Now, adding both the binomials, we get:

Distributing the positive sign inside the second binomial, we get:

Now, combining like terms using the commutative property of addition, we get:

Simplifying the above expression, we get:

Therefore, the resulting addition of the given binomials is 
Hence, option C is the correct answer.
Answer:
A.The expression represents the price paid
B.
; everything means the same thing as the first.
Step-by-step explanation:
For a. we can tell what the expression means by re-reading the problem. We know that the 15 is the price per goby fish and that 10 is the price per shrimp. Since there is an equal number of each in each bag the x represent the number of goby fish or shrimp in the bag. The answer to the equation will be the price paid. Another expression you could use is the following.

This is an unfactored version of the first on where x is factored out. Here everything means the same thing it's just a different expression.