Question

factor completely 4x^2 - 24x - 8

This is just simple factoring. I believe it may be prime, because I can only get as far as factoring out the 4. I end up with 4(x^2 - 6x - 8). I am unable to factor what's inside the parenthesis, so I am assuming the expression is Prime.

Answer 1

You can use the X method. Are you familiar with that?

Answer 2

Use the quadratic formula. It's never-fail. Do you know it?

Answer 3

Heres a cool song if you want to remember it. https://www.youtube.com/watch?v=H_7lNT9oDzI

Answer 4

no I don't know it, and what does a song have anything to do with anything?

Answer 5

oh im sorry i replied to the wrong thread.
someone else is working with the quadratic formula

Answer 6

The song helps your remember the quadratic formula. It's quite something, all the variables you have to remember.\[\frac{ -b \pm \sqrt{(b)^{2}-4ac} }{2a }\]If you can remember all that then maybe you don't need the song.

Answer 7

Anyways, factor your expression inside the parenthesis using the quadratic formula and the fact that in your expression, a = 1, b = -6, c = -8\[\frac{ -(-6)\pm \sqrt{(-6)^{2}-4(1)(-8)} }{ 2(1) }\]

Answer 8

That gives you\[\frac{ 6\pm \sqrt{36+32} }{2 }\]or\[\frac{ 6+\sqrt{68} }{ 2 } , \frac{ 6-\sqrt{68} }{ 2 }\]

Answer 9

Yep thats right ^. lol IMStuck how much time do you spend on here. you helped me once too.

Answer 10

The first one gives you x = 7.123 and the other one gives you x = -1.123

Answer 11

I spend literally almost all day on here. I'm a teacher (going through withdrawals) and want to keep up with my math all year long. I tutor on tutor.com, too! I love love math!

Answer 12

I am not trying to solve an equation. I just need to factor the problem. The answer should be in the form of ( )( ). This is why I think it is prime.

Answer 13

It can factor into (x-7.123)(x+1.123). It's not prime.

Answer 14

No polynomial is EVER unfactorable, ever!!!! The quadratic formula can factor any second degree polynomial ALWAYS.

Answer 15

...trust me...

Answer 16

You can factor out a 4.

Answer 17

can not be factored

Answer 18

The quadratic formula is used for factoring.

Answer 19

\(4x^2 - 24x - 8\)

\(= 4(x^2 - 6x - 2)\)

Now it's factored completely.

Answer 20

Thank you. We are not that far in the class to use the quadratic formula and there have problems where the answer has been prime, so I just thought this one was prime. At this point in the class I believe it has to equal the exact number in the polynomial. For example, 7.123 * 1.123 = 7.999. Thanks MaxwellSmart...I wasn't sure if that was considered to me completely factored or not.

Answer 21

You're welcome.