Question

What is the factored form of x^6-9?

Answer 1

It is the last one: (x^3 + 3(x^3 -3)

Answer 2

Answer: (x³ + 3)(x³ - 3)

Explanation: A variable taken to any even power is a perfect square. Its factors will have exponents equal to one-half the original power.

In this case, x⁶ would therefore be a perfect square.

Since 9 is also a perfect square,

what we have here is the difference of two squares.

That can be factored as the product of two binomials,

one with a plus and one with a minus.

So we have (   +   )(   -   ).

Now ask yourself "what are the factors of x⁶ that are the same?"

Remember the rule is that those factors will use

one-half the exponent on the original.

So the factors of x⁶ that are the same are x³ and x³.

The factors of 9 that are the same are 3 and 3.

So our answer is (x³ + 3)(x³ - 3) and that's all there is to it.