Question

given the binomials (x-2),(x-1),(x+2) and (x-4), which one is a factor of f(x)=3x^3-12x^2-4x-55?

Answer 1

http://img.docstoccdn.com/thumb/orig/106604345.png

Answer 2

ok i got (x-2) is that right?

Answer 3

@kc_kennylau

Answer 4

does f(2) = 0?

Answer 5

oh no. but (+4) does

Answer 6

3x^3-12x^2-4x -55
0 6 -12 32
2 3 -6 -16 not0

yeah, a run of syntheticD says 2 is bad



3x^3-12x^2-4x -55
0 12 0 -16
4 3 0 -4 not0

i dont htink 4 is a good fit either

Answer 7

3x^3-12x^2-4x -55
0 3 -9 -13
1 3 -9 -13 not0

lol, i seems to be out as well

Answer 8

im going to try (x-1)

Answer 9

i think that works!

Answer 10

last one better be it ..

3x^3-12x^2-4x -55
0 -6 36 -64
-2 3 -18 32 not0

ugh, i need more sythD practice ....

Answer 11

Well in fact none of them works, but you can keep trying :)

Answer 12

http://www.wolframalpha.com/input/?t=crmtb01&f=ob&i=factorize%203x%5E3-12x%5E2-4x-55

Answer 13

i see that lol

Answer 14

i was assuming one of them was right arg

Answer 15

what about (x-5)?

Answer 16

im going to try

Answer 17

x-5 fits, but that wasnt an option you gave us .... so the good news is i dont need synthD practice afterall :)

Answer 18

lol thnk you!!