Answered

IDNLearn.com provides a user-friendly platform for finding and sharing knowledge. Our platform is designed to provide quick and accurate answers to any questions you may have.

factor completely 3x ^2 -27

Sagot :

Both terms are multiply of 3, so you can factor 3 out;

3(x² - 9)

Now, we can see that x² - 9 is difference of two perfect squares

Recall that a² - b² = (a+b)(a-b)

So we have x²-9 = (x+3)(x-3)

So we can factor more here; 3(x²-9) = 3(x+3)(x-3)

Final answer: 3(x+3)(x-3)
First, factor out a 3.
3(x² - 9)

In any quadratic ax² + bx + c, we can split the bx term up into two new terms which we want to equal the product of a and c.
In this case, we have x² + 0x - 9. (the 0x is a placeholder)
We want two numbers that add to 0 and multiply to get -9.
Obviously, these numbers are 3 and -3.

Now we have 3(x² + 3x - 3x - 9).
Let's factor.
3(x(x+3)-3(x+3))
3(x-3)(x+3)

There are multiple shortcuts which you could make here, FYI:
Instead of splitting the middle, if your a value is 1, you can go straight to that step (x+number)(x+other number).
Whenever you have a difference of squares, like a²-b², that factors to (a+b)(a-b).
Thank you for using this platform to share and learn. Don't hesitate to keep asking and answering. We value every contribution you make. Your questions deserve precise answers. Thank you for visiting IDNLearn.com, and see you again soon for more helpful information.