Final answer:
To find the sum, combine like terms in the given expressions.
Step-by-step explanation:
To find the sum of the given expressions, we need to combine like terms.
7x + (x² - 4) + (x² + 2) = 7x + 2x² - 4 + 2 = 2x² + 7x - 2.
Learn more about Combining like terms in algebraic expressions