Final answer:
To simplify (A²-2a²)-(3a²-4a³), combine like terms: A² - 5a² + 4a³.
Step-by-step explanation:
To simplify the expression (A²-2a²)-(3a²-4a³), we can combine like terms. First, distribute the negative sign to the terms inside the parentheses:
(A²-2a²)-(3a²-4a³) = A² - 2a² - 3a² + 4a³
Next, combine the like terms:
A² - 2a² - 3a² + 4a³ = A² - 5a² + 4a³
So, the simplified expression is A² - 5a² + 4a³.