How do you do this problem ?

Question

Factor the polynomial completely. If the polynomial cannot be factored, write prime.
12x^2 - 42x - 24

6(2x + 1)(x - 4)
(12x - 6)(x + 4)
6(2x - 1)(x + 4)
prime

Answer 1

Hi,

12x² - 42x - 24 has a GCF of 6. Divide it out of every term.

6(2x^2 - 7x - 4)

Now factor the trinomial.

6(2x + 1)(x - 4)


I hope that helps!! :-)

Answer 2

1. You should notice that every coefficient is divisible by 6.
So factor out a 6 first.
6 * (2x^2 - 7x - 4)

2. Now set up your parenthesis.
Since the last term is neg( - ) then your signs are one of each.
( - )( + )

3. List the factor pairs of the first and last coefficient.
1*2 and 1*4, 2*2
Now mix-n-match them to get that 7 in the middle term.
Using 1*2 and 2*2 will not get the combination you need.
But if you try:
(2*4) - (1*1) then you get a 7.

4. set up your parenthesis so the inside and outside match up with above.
6 * (2x - 1) * (1x + 4)
Oustide is 2x * 4 = 8x
Inside is -1*1x = -1x
Put them together to get that 7x.

Answer 3

12x^2 - 42x - 24 = 6(2x + 1)(x - 4)

Answer 4

Use this source!!!