Factoring a trinomial

please help me solve this

-x^2 + 14x - 45

Question

Factoring a trinomial

please help me solve this

-x^2 + 14x - 45

kayders1997 · Answer

Me personally I would multiply everything by -1 right off the bat

kayders1997 · Answer

Than the-x^2 will be positive so it will be a little easier to figure out

anonymous · Answer

but...doesn't this need to end up in parentheses? a solved a different one earlier and the answer ended up looking like this: (n-18) (n+4)

mathmale · Answer

Yes:  If you follow kayders' advice, you'll get (-1)(x^2 - 14x - 45).
Yes, to complete this factoring you must factor x^2 - 14x - 45.

kayders1997 · Answer

Yes it needs to end up in parenthesis but you need to find two numbers that multiply to -45 and add to 14x if you don't want to multiply by the -1

mathmale · Answer

What are sets of integer factors of 45?  Which set could add up to 14?

mathmale · Answer

What are sets of integer factors of -45?  Which set could add up to -14?

kayders1997 · Answer

Wait mathdale

anonymous · Answer

i think you both have the numbers a little bit mixed up. after the -1 it ends up like this right? 

$$x ^{2} - 14 + 45$$

(just for my own clarification.)

kayders1997 · Answer

Wouldn't it be multiply to 45 that adds up to -14 if you multiply by the -1

kayders1997 · Answer

Don't forget your x with the -14 so -14x

anonymous · Answer

yep just went a little too fast. I know it's there

kayders1997 · Answer

Okay good now what is two numbers that multiply to 45

mathmale · Answer

"Yes:  If you follow kayders' advice, you'll get (-1)(x^2 - 14x - 45).
Yes, to complete this factoring you must factor x^2 - 14x - 45."

I'm sticking with my previous statement.  (-1) becomes just another factor of the original expression.  Still have to factor x^2 - 14x - 45.

anonymous · Answer

these are the only ones I could come up with

5x9

3x15

45x1

kayders1997 · Answer

Good now which one can add to 14 remember it has to be -14x

anonymous · Answer

- (x - 9) (x - 5)

what do you think?

mathmale · Answer

The three factors are (-1), (           ) and (           ).
Bookish One:  You could check that yourself, and I strongly encourage you to do so.

kayders1997 · Answer

yes good

kayders1997 · Answer

That's the answer :)

anonymous · Answer

thank you for your help!

kayders1997 · Answer

You're welcome! If you need help in the future you can message me or put my name in the chat for the question for asking :)

kayders1997 · Answer

*your asking

anonymous · Answer

*you're asking ;)

kayders1997 · Answer

Not the best at grammar :P I'm a math person

anonymous · Answer

same for me except the other way around XD

kayders1997 · Answer

Lol everyone is good at their own subjects :)