Question

How? (2x^2 - 3x - 4)(x + 7)​

Answer 1

Answer:

$2 {x}^{3} + 11{x}^{2} - 25x - 28$

Step-by-step explanation:

Using foil method, Multiply the first term

$2 {x}^{2} \times x = 2 {x}^{3}$

Next, Multiply the Outer term in each parenthesis. (2x^2 and 7

$2 {x}^{2} \times 7 = 14 {x}^{2}$

$2 {x}^{2} \times 7 = 14 {x}^{2} \: \: \: 3x \times - x = - 3x$

Then, Multiply the Inner Terms (-3x,-4,7) in each parenthesis

$- 3x \times 7 = - 21x$

$- 4 \times x = - 4x$

Then multiply the last term (-4 and 7).

$- 4 \times 7 = - 28$

Combine it you have

$2 {x}^{3} + 14 {x}^{2} - 3 {x}^{2} - 21x - 4x - 28$

which simplify to

$2 {x}^{3} + 11 {x}^{2} - 25x - 28$