Question

What is the product? (2x-1)(x+4) O 2x24 O 2xả44 O 2x²+7x-4 O 2x²-7x-4

Answer 1

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 2

Answer:

$C. 2x^2+7x-4$

Step-by-step explanation:

1) Distribute.

$(2x-1)(x+4)\\2x(x+4)-1(x+4)$

2) Distribute.

$2x(x+4)-1(x+4)\\2x^2+8x-1(x+4)$

3) Distribute.

$2x^2+8x-(x+4)\\2x^2+8x-x-4$

4) Combine like terms.

$2x^2+8x-x-4\\2x^2 + 7x - 4$