SOLUTION: Please help me in solving x^4-64. This is how I believe it's supposed to be solved x^4-64 I take the 4th root of x and get x, and the 3rd root of -64 and get -4, which can be sim

Algebra ->  Square-cubic-other-roots -> SOLUTION: Please help me in solving x^4-64. This is how I believe it's supposed to be solved x^4-64 I take the 4th root of x and get x, and the 3rd root of -64 and get -4, which can be sim      Log On


   

Question 201007: Please help me in solving x^4-64.
This is how I believe it's supposed to be solved
x^4-64 I take the 4th root of x and get x, and the 3rd root of -64 and get -4, which can be simplified further to 2. My answer then is x-2. On the other hand I looked at factoring x^4-64 by factoring like so, (x^2+8)(x^2+8), then (x^2+8)(x+4)(x-2)but this would give me a middle term. Please help.
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Solve(?):
x%5E4-64
Well, since this is not an equation (it's an expression) you really cannot solve it. The best you can do is simplify it, so let's do that!
Simplify:
x%5E4-64 Notice that this the difference of two squares %28x%5E2%29%5E2-%288%29%5E2and it is factorable thus:highlight_green%28A%5E2-B%5E2+=+%28A%2BB%29%28A-B%29%29, so...
highlight%28x%5E4-64+=+%28x%5E2%2B8%29%28x%5E2-8%29%29