Thread: Factor by grouping

Cant seem to figure this out. Any ideas or tips? Thanks for the help

Hi! 1 is a root of your polynomial, so by polynomial long division you can find out the factors.

-1 is also a root (one checks this by trying the factors of the constant coefficient -1).

So if Im getting the answer of C is that wrong?

Of course that is wrong, C neither has the root 1 nor the root -1.

Ok I redid it and think I got the right answer, I first took

2x^3 + x^2 - 2x - 1

(2x^3 + x^2) - (2x - 1)

x^2( 2x + 1) + 1(2x + 1) found the common factor(not sure if thats the right term)

So my final answer would be

(2x + 1)(x^2 +1) Again this is factoring by grouping so if anyone has any input thanks

It is not right, for the same reason as in the previous post. The - in the second row should be a plus, then it will work out. But the method is right and effective.

Dangit, Ok Ill try doing this again, just not getting it