Final answer:
To find A + B, combine the like terms and simplify the expression. The sum is -3x² - 12x + 3 + 2z.
Step-by-step explanation:
To find A + B, we add the corresponding terms together. 2z - 7x² + 3 + 4x² - 12x
Combining like terms, we have (-7 + 4)x² + (-12)x.
Therefore, A + B = -3x² - 12x + 3 + 2z.
Learn more about Adding expressions