Answer: The third option, O 2x²+7x-4
Explanation:
We can use the "FOIL" method. We take the following four sets, multiply them together, then add them for our final answer.
-> first
-> last
-> inner
-> outer
What does this look like mathematically?
-> first = (2x - 1)(x + 4) = 2x * x = 2x²
-> last = (2x - 1)(x + 4) = -1 * 4 = -4
-> inner = (2x - 1)(x + 4) = -1 * x = -x
-> outer = (2x - 1)(x + 4) = 2x * 4 = 8x
-
2x² - 4 - x + 8x
2x² + 7x - 4
O 2x²+7x-4