errr I don't know how to do this. It goes b. 3x^2 - x - 4, factor. Can anyone please show how to do this? Thanks! :D
+118723 3x^2 - x - 4,
Alan can probably do this in his head but I cannot
$$3x^2 -1 x - 4$$
I look for 2 numbers that multiply to 3*-4=-12
since they mult to a negative - one must be pos and the other neg.
they ALSO must add to -1 SO the bigger one is neg and they are only one apart.
That is easy, -4 and +3
Now make -1x=3x-4x
$$3x^2 -1 x - 4$$
$$3x^2+ 3x-4x - 4$$
NOW factor this in pairs
=3x(x+1) -4(x+1)
=(3x-4) (x+1)
Is it 3x^2 - x - 4?
If so, there is not what you'd call a neat solution.
Maybe you mistyped it? Please check and confirm! 
+118723 3x^2 - x - 4,
Alan can probably do this in his head but I cannot
$$3x^2 -1 x - 4$$
I look for 2 numbers that multiply to 3*-4=-12
since they mult to a negative - one must be pos and the other neg.
they ALSO must add to -1 SO the bigger one is neg and they are only one apart.
That is easy, -4 and +3
Now make -1x=3x-4x
$$3x^2 -1 x - 4$$
$$3x^2+ 3x-4x - 4$$
NOW factor this in pairs
=3x(x+1) -4(x+1)
=(3x-4) (x+1)
