Question 70646: Factor each polynomial by grouping the first two terms and the last two terms.
x^3- 4x^2 + 2x -8
I am confussed an need some help. Thanks.
Answer by venugopalramana(3286)   (Show Source):
You can put this solution on YOUR website! Factor each polynomial by grouping the first two terms and the last two terms.
F(X) = x^3- 4x^2 + 2x -8
WRITE ALL FACTORS OF -8...
+ OR - 1,2,4,8
TRY THEM AS A FACTOR BY CHECKING F(...)
SAY F(1),F(-1)..ETC
F(4)=4^3-4*4^2+4*2-8=0..HENCE X=4 IS A ROOT...SO...X-4 IS FACTOR.
NOW DIVIDE F(X) WITH X-4.WE GET
4|1-4+2-8
.|0+4+0+8
----------------
..1+0+2+0=REMINDER
X^+0X+2=X^2+2 IS THE QUOTIENT.
NOW THIS HAS NO MORE REAL FACTORS SO WE LEAVE IT HERE AND SAY
F(X)=(X-4)(X^2+2)
OK
I am confussed an need some help. Thanks.
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