Question

i have to solve the polynomail equation by factoring. This is the problem 9x2+36x-189. (The 2 signifies "squared". I get to 9(x+7)(x-3) and I am lost. Someone help please :]

Answer 1

what is the 'solution' you are needing?

Answer 2

i must solve the polynomial equation.

Answer 3

what does 'solve' mean in this context?

Answer 4

as in for zero products

Answer 5

ok.. then you are looking for the zeros, or roots of the equation; and not just the factored form right?

Answer 6

9x2+36x-189 ; /9

9 (x^2 +4x -21) ; the 9 is useless to us in finding zeros so toss it

x^2 +4x -21 ; factor it

Answer 7

(x+7)(x-3) are good

now we want to know when either one of them equals ZERO

Answer 8

x+7 = 0; when x = ?

x-4 = 0; when x = ?

Answer 9

im sorry after reviewing my notes, it can aslo be solving a quadriatic equation by factoring. it must be factored out. A more simpler problem would be: \[n ^{2} +9n+14=0...n ^{2} turns into (n+7)(n+2).. therfore, n+2=0 \in order \to get n by itself subtract 2 from each side leaving you with n=-2.. again with n+7=0 \in ordcer \to get n alone subtract 7 from each side. n=-7.. The set is (-2,-7)\]

Answer 10

makes no sense lol

Answer 11

9(x+7)(x-3) is a good 'solution' then

Answer 12

Ok I understand up to that Im just just confused as to where the 9 goes.

Answer 13

9 = 0 never, so it plays no part in finding zeros; other than that, it just sits on the outside looking in

Answer 14

No, 9(x+7)(x-3) is not the solution.. Ok Thank you for your help I may just review my lesson over again because I don;t beleive we would just toss the 9 out like that. it is still part of the problem and when checking my answer it does not match up if i just simply toss the 9. thank you anywy

Answer 15

when you factor you leave it

Answer 16

in fact u should always leave it

Answer 17

the roots of the equation are the same whether you solve for 9=0 or not :)

Answer 18

just in the last step

Answer 19

you set all the factors in the product equal to zero

Answer 20

ok like i said, Thank you anyway, amistre64! I aprrciate it! I think it just would be best for me to re-review my lesson considering i have doubts.

Answer 21

with something like

9(x-3)(x+5) =0

you set 9=0 , or x-3 =0 or x+5=0

Answer 22

(x+7)(x-3) has the same exact roots as 9(x+7)(x-3) which has the same exact roots as 174638485736738459858(x+7)(x-3)

Answer 23

the first eqn is a false statement , you ignore it because its false, it gives no answer

Answer 24

9=0 is not true for any x

Answer 25

ok thank you elecengineer!!!!!!!!!!!!!!!!! that is exactly what i was confused about so you do set the 9 to 0! perfect! thank you so much!! :]

Answer 26

it gives no extra solutions

Answer 27

....... you can set 9 equal to 62 if you want and get the same results lol

Answer 28

amister im sorry but you are severely confusing me furthger than i already am

Answer 29

lol:P

Answer 30

thats because im trying to teach you that you need to see the problem for what it is instead of just trying to apply blind methods.

Answer 31

prob best to leave all the constant factors in , until the very last step , instead of just tossing them away. Even though, yes , you know what you are doing , it is a tad confusing to someone that doesnt really know what they are doing.

Answer 32

set 9 = 0 is nonsense language; 9=9 and can not be "set" to 0; since 9=9 it is not a 'zero' of the function....ever :)

Answer 33

amistre you are being a little to rude to me and making me feeling as if you are speaking down to me. please do not do that. I said ido not understand and rather than confusing myself further i will simply go over the lesson again.. i thanked you for your time and for your help that is all.

Answer 34

or you could say "divide "

Answer 35

ok thank you for your help and time

Answer 36

Hokay now....

Answer 37

but thats spliting hairs lols

Answer 38

toss it, ignore it, put it in the corner, leave it out on the doorstep in the rain .... doesnt matter what you do with it, it serves no purpose in finding the roots of the function

Answer 39

santani; trust me, if I were 'being rude' to you the whole world would no about it; but since your feeling upset about how you have read my responses; I will apologise.