I posted this earlier in the day but no one answered. Can anyone help with these problems?

Factor completely:
1. 8x3 + 2x3 – 12x –3
2. 27x3+8
3.125 – 8x3

2 answers

The second one is the sum of perfect cubes, for which you have a formula.

The third is the difference of perfect cubes, same formula almost.

The first I assume is 8x^3+2x^2-12x-3=0 This is not going to factor nicely, I suggest you graph it on your calculator, and take a look at the roots. Not a nice function.
I don't have a graphing calculator. Is there another way to find the roots so I can factor the problem? And I'm sorry I don't know what formula you are talking about for 1 and 2.