- Thread starter galabingo
- Start date

- Joined
- Nov 12, 2017

- Messages
- 7,939

4(2x+1)(3x-1)^3[...].

Can you finish that step, so we can see how well you do this far?

Ideally, we want to see all the work you did on your own, to see whether you went in the wrong direction, or just made little mistakes along the way.

4(2x+1)(3x-1)^3 x (3x-1)

And

4(2x+1)(3x-1) x 3(2x+1)(3x-1)^2

4(2x+1)(3x-1) x ((3x-1)+3(2x+1)(3x-1)^2)

Therefore

((3x-1)+3(2x+1)(3x-1)^2)= (3x-1) +(6x+3)(3x-1)^2)

=(3x-1) +(6x+3)(9x^2-6x+1)

=(3x-1) + (27x^3+36x^2+6x +27x^2-18x+3)

=3x-1+27x^3+36x^2+6x +27x^2-18x+3

=-9x +27x^3+63x^2-12x+3

=-21x+27x^3+63x^2+3

=-7x+9x^3+21x^2+1

Should I then use long division?

Not sure what to do, I guess it is easy as simplifying was not the main point of the exercise I’ve been doing but I’m still confused

- Joined
- Nov 12, 2017

- Messages
- 7,939

But the important thing is that you must

- Joined
- Sep 15, 2019

- Messages
- 50

You could use either a different variable but in general I would use a * or a dot. Even if x isn’t a variable, people might mistaken it to be and x

But the important thing is that you mustnotdistribute (expand) everything. There was a reason we factored out the GCF at the start! (Did you not compare what I said to do with the form given for the answer? Factors are your friends, here, so you don't want to send them away.) So everything after "therefore" is going in the wrong direction; you just need to correct the part above that, and then expandonlywhat's inside my [ ... ].