Factor: $\displaystyle x^3+4$ ?
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Sum of cubes: $\displaystyle a^{3} + b^{3} = (a + b)\left(a^{2} - ab + b^{2}\right)$
Ok. So what would be the answer? Would $\displaystyle (x+4)(x^2-4x+16)$ be correct ?
Not quite. Notice how 4 represents $\displaystyle b^{3}$. If that's the case, what is b?
I don't get it. :/
b seems to be 4 to me.
This is what I'm saying: $\displaystyle b^{3} = 4$ Solve for b. If $\displaystyle b = 4$, then $\displaystyle b^{3} = 64 \neq 4$
but $\displaystyle b^{3} = 64$ does equal 4. Can you please fully explain the problem out to me. I foiled my answer 5 times and every time I got $\displaystyle x^3+64$
Oh! I see where I messed up. What I needed factored was $\displaystyle x^3+64$ not $\displaystyle x^3+4$ which I posted. I'm really sorry.
In that case, your original answer was right.
Thank you. Sorry again for the confusion.
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