Question

Factor the trinomial: (x-4)^2+3(x-4)-18

Answer 1

u^2+3u-18 <---do you know how to factor this?

Answer 2

(x-4){(x-4)+3}-18
(x-4){x-1}-18

Answer 3

@myininaya yes. (u+6)(u-3)

Answer 4

great replace u with x-4

Answer 5

expand your first bracket you get x^2-8x+16 then +3x-!2(this from expanding your second bracket) -18
then you end up with x^2-5x-14
the you use the quadratic formula to find out the value of x..
i ended up with 7 and -2

Answer 6

\[(x-4)^2+3(x-4)-18\]
Replace x-4 with u
\[u^2+3u-18\]
(u+6)(u-3)
Replace u back with x-4.

Answer 7

@myininaya so I'd have [(x-4)+6]^2+3[(x-4)-3]-18?

Answer 8

(u+6)(u-3) is factored form
Replace the u's here with x-4 like this:
(x-4+6)(x-4-3)
The simplify inside the parenthesis.

Answer 9

Then*

Answer 10

Okay. What I wrote wasn't simplified. So I just needed to factor using substitution. Okay. I started out doing that, but I don't think I was doing it correctly. Thank you much!!

Answer 11

Do you want me to give you another one to try?
And also don't forget to write -4+6 as 2 and -4-3 as -7

The final answer would be (x+2)(x-7)

Answer 12

If you want to, try to factor this one.
\[(x-1)^2+5(x-1)+6\]

Answer 13

Okay, give me a second :)

Answer 14

u^2+5u+6

(u+3)(u+2)

(x-1+3)^2+5(x-1+2)+6

2x^2+5x+6

... uhhhm I'm stuck. Haha.

Answer 15

Now you are doing something weird that you were doing before.
Get rid of that third line and everything after.

Answer 16

Replace u with x-1
so we will be replacing the u's in (u+3)(u+2) with [x-1]
(x-1+3)(x-1+2)
=
(x+2)(x+1)

Answer 17

@myininaya you are correct with you (x-7)(x+2)

Answer 18

Ohh... Oops. Sorry.

Answer 19

\[(kitty+bat)^2+3(kitty+bat)+2\]
replace kitty+bat with u
\[u^2+3u+2=(u+2)(u+1)\]
So to factor \[(kitty+bat)^2+3(kitty+bat)+2\] we say \[(kitty+bat+2)(kitty+bat+1)\]

Answer 20

Ahh. I try to do things to fast. My brain gets ahead of itself... gets all jumbled. Haha, it made sense before kitty+bat, but that's a good way to remember it. Thank you :)

Answer 21

lol. I'm just saying whatever those things are as long as they are the same you can always replace with a simple substitution such as u and factor and then go back and replace u with what it was before.

Answer 22

Yes, I see. XD

Answer 23

\[(x^2-1)^2+4(x^2-1)+4\]

So we know how to factor: \[u^2+4u+4\]

Answer 24

We say \[(u+2)^2\]
now do you see what u should be here?

Answer 25

Humma? You complicated it with x^2 in each of those. Give me a second.

Answer 26

Ohhhh. Okay.

Answer 27

Well instead of x^2-1 we see u so we replaced x^2-1 with u so we can go back and say well u was x^2-1.
So ...
\[(u+2)^2=(x^2-1+2)^2=(x^2+1)^2\]

Answer 28

Blahhh. This page keeps freezing on me. I've been trying to type a reply for the last five minutes.

Answer 29

Yesh. I got that. :/

Answer 30

Was that going to be your answer? :)

Answer 31

Twas...

Answer 32

I even have it written down. :)

Answer 33

Good job. :)

Answer 34

Thank you for helping me :) I really appreciate it.

Answer 35

Posting... posting... posting... lol.

Answer 36

My computer hates this site.

Answer 37

I don't think yours is the only one.

Answer 38

There is a little lag. I think it might be from so many people using it. I'm not sure.