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Mathematics 14 Online
OpenStudy (anonymous):

7x^3-5x^2-63x+45 use the zero x=3 to find all the zeros of the polynomial function

OpenStudy (mathteacher1729):

Do you know how to do polynomial division?

OpenStudy (anonymous):

is that synthetic division?

OpenStudy (mathteacher1729):

Yeah, different names, same process.

OpenStudy (anonymous):

i know how but there has to be a faster wayy or id be testing like 13 roots

OpenStudy (anonymous):

oh now i get it.. thanks emirzoyan

OpenStudy (anonymous):

wlecome :)

OpenStudy (anonymous):

welcome*

OpenStudy (mathteacher1729):

You're already given one root. So if you divide by (x+3) you'll end up with a quadratic equation. Finding the roots of the quadratic should be easy.

OpenStudy (anonymous):

oh like divide the whole thing by x+3

OpenStudy (mathteacher1729):

Arrrgh, no no no, not +3, sorry. :( If +3 is a ROOT that means (x - 3 ) is a FACTOR. (because if x = +3 then (x- +3) = 0

OpenStudy (mathteacher1729):

So divide by (x-3)

OpenStudy (anonymous):

ok no worries

OpenStudy (anonymous):

okay i got 7x^2+16x-15 but im lost on how to factor it

OpenStudy (mathteacher1729):

Since 7 is the coefficient of x^2 you know that it's going to factor (7x ) * ( x ) can you fill in the rest?

OpenStudy (anonymous):

no im having trouble with that

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