x^2+bx+c

[bobisaka]

I use one of the rules which states 'when we factor a trinomial, we look at the signs of its terms first to determine the signs of the binomial factors'.
For the following trinomial: x^2-3x+2, its binomial factors' should be (x-m)(x-n).
However, when i use the step no.2 to find m and n, c = positive and bx = negative, does the the result become (x+m)(x-n). If i am not mistaken all the results for step 2, so far, has not given me negative answers for both m and n to follow the (x-m)(x-n) factors rule.


step 1. (x - ) (x- )

step 2. Find m,n

c = -2*-1 = 2 (positive)

bx = -2+-1=-3 (negative)

...

Your clarification is appreciated.

 

[bobisaka]

Ignore this thread, i figured it out.

I have not figured out how to delete the thread.

 

[Dr.Peterson]

Presumably what you figured out is that in your method, m and n are assumed to be positive numbers, which turn out to be 2 and 1 (not -2 and -1). Your method is intended to allow you to ignore signs while you do the second step, but you didn't ...

 

[HallsofIvy]

Also, the coefficient, that is either positive or negative, is not "bx" it is just "b".