Answer: The third option, O 2x²+7x-4
Step-by-step 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
Answer:
[tex]C. 2x^2+7x-4[/tex]
Step-by-step explanation:
1) Distribute.
[tex](2x-1)(x+4)\\2x(x+4)-1(x+4)[/tex]
2) Distribute.
[tex]2x(x+4)-1(x+4)\\2x^2+8x-1(x+4)[/tex]
3) Distribute.
[tex]2x^2+8x-(x+4)\\2x^2+8x-x-4[/tex]
4) Combine like terms.
[tex]2x^2+8x-x-4\\2x^2 + 7x - 4[/tex]
