Final answer:
Combining like terms of the polynomial 2x + 3z - x + 5z results in x + 8z, which corresponds to answer option C). Like terms are combined by adding or subtracting the coefficients, ensuring the final answer is checked for reasonableness.
Step-by-step explanation:
To combine like terms and simplify the polynomial 2x + 3z - x + 5z, we look for terms that have the same variable raised to the same power. In this case, 2x and -x are like terms as well as 3z and 5z.
Combining the x terms:
And combining the z terms:
Putting it all together, we get:
x + 8z
Therefore, the simplified polynomial is x + 8z, which corresponds to option C).
Finally, we check if the answer is reasonable by verifying that the combined terms make sense arithmetically.