how do you factor 27x^3 - 48x when they have no common numbers?

Question

oaktree · Answer

Yes they do...they both share 3x.

anonymous · Answer

so 3x would go on the outside of the parenthesis? like this: 3x(x  )(x   ) right?

oaktree · Answer

Sort of... it would be 3x(9x^2-16).

oaktree · Answer

Then use difference of two squares to factor the 9x^2-16 into (3x+4)(3x-4)

oaktree · Answer

So your final answer is 3x(3x+4)(3x-4)

anonymous · Answer

thank u so much!

oaktree · Answer

You're welcome. But do you know the difference of two squares?

anonymous · Answer

isn't when u draw a box and factor that way?

oaktree · Answer

NO! What you do is square root the first and last terms (only works when you can do this evenly and when the terms are being subtracted)

oaktree · Answer

Your two factors are those two square roots, except one is plus and one is minus.

anonymous · Answer

oohhh yeaaa i remember that...i didn't know it was called difference of 2 squares

oaktree · Answer

Like (x+4)(x-4)

oaktree · Answer

Oh. That's because it's a difference (subtraction) of two square numbers.

anonymous · Answer

ohh ok ... thanks for explainin that