Question

Factor completely:
n^2-9n+8
Please help.

Answer 1

what are some factors of 8, that add to -9?

Answer 2

(the factors can be positive or negative)

Answer 3

-8 and -1 ?

Answer 4

good

Answer 5

(n-8)(n-1)
n=8 or n=1
am I right ?
@UnkleRhaukus

Answer 6

your first line is all this question is asking for

if it was n^2-9n+8=0 then your would be right that x=8 or 1
but there was no equal sign in the original expression

Answer 7

I know, but the whole point of this question is I think to find what n could be..

Answer 8

if you want to check it
just expand the brackets, you should get the expression in the question

(n-8)(n-1)=(n×n)+(n×-1)+(-8×n)+(-8×-1)

Answer 9

oh i thought you just had to Factor completely

Answer 10

oh... I see. thank you;D

Answer 11

but if this was just a sub question to a larger problem , then your probably right

Answer 12

ohh.... could you help my with this one too:
7x^2-45-28
what should I do with the 7?
@UnkleRhaukus

Answer 13

this one isn't so simple

i would set it equal to zero , and apply the quadratic formula

\[ax^2+bx+c=0\]
\[x_{1,2}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}\]

\[ax^2+bx+c=(x-x_1)(x-x_2)\]

Answer 14

but they want me to factor it Completely...

Answer 15

(x−x_1)(x−x_2) is the factored form

Answer 16

7x^2-45-28=0

what is a,b,c?