Given:
If we need to find what is, we can solve for a and plug it in. Let's use the quadratic formula to solve for a. The quadratic formula is:
and
Let's identify our a, b, and c:
a: 1
b: 3
c: 9
Plug in the values into the quadratic formula:
Simplify everything under the radical:
Simplify the radical:
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Let's solve for the second part of the quadratic formula. Everything will be the same, so we can just replace the + with a -.
and
These two are your answers. Now, since we know what a is, let's cube this value:
Simplify:
You will get the same answer if you cube both of the quadratic answers. So, your final answer: