OpenStudy (anonymous):

Help,

OpenStudy (anonymous):

OpenStudy (anonymous):

@kirbykirby @ChipperJay*

OpenStudy (kirbykirby):

You can just evaluate it by plugging in $$x=-2$$ into the polynomial and you'll get the answer (since it's multiple choice)

OpenStudy (anonymous):

D

OpenStudy (kirbykirby):

yup :) I mean you can d the long division method in which the remainder will be the answer, but it's probably longer to do and since it's multiple choice, why not use a faster solution :o ?

OpenStudy (anonymous):

i know o.o can u help me with another

OpenStudy (anonymous):

i put B. but its wrong. :/ dont understand

OpenStudy (kirbykirby):

o.o that is strange... that should be the correct answer

OpenStudy (anonymous):

i know o.O and it cant be A

OpenStudy (kirbykirby):

i even double checked it on Wolfram Alpha

OpenStudy (kirbykirby):

I dunno someone must have assigned the answer to the wrong letter :S because B is definitely right !

OpenStudy (anonymous):

yeah, im going to pick A :S

OpenStudy (kirbykirby):

the system gives you multiple tries?

OpenStudy (anonymous):

twice, first time i picked letter B and it was marked wrong.

OpenStudy (kirbykirby):

ah

OpenStudy (kirbykirby):

well it would be good to bring this up to your teacher

OpenStudy (anonymous):

yeah, i am going to email her.

OpenStudy (anonymous):

ty kirby :)

OpenStudy (anonymous):

OpenStudy (kirbykirby):

Ah this is an application of the Factor Theorem. Essentially, if you find that when plugging in x=-4 and x=-1 and the polynomial evaluate to 0 (for both of these x values), then these x values are zeroes.

OpenStudy (kirbykirby):

You can also think of it this way: A zero is a value of x such that y=0 (the value that crosses the x-axis). So plugging in a value of x that is a zero, should give y=0

OpenStudy (anonymous):

hmm A

OpenStudy (kirbykirby):

yep =]

OpenStudy (anonymous):

yayyy!!! :D

OpenStudy (anonymous):

ty

OpenStudy (kirbykirby):

yw!