(1/8x^3 -3/10x -1/4) (-1/8x^3 +3/10x -1/4)?

Question

Simplify the answer.Use integers of fractions for any number in the expression.

Answer 1

First I got rid of the fractions then multiplied it out After multiplying by 40/40, I get

(5x^3 - 12x - 10)(-5x^3 + 12x - 10)  <== I'll spread this out

-25x^6  + 60x^4  -50x^3

______+ 60x^4  ______ -144x^2  +120x

____________+50x^3 ________ -120x  +100

--------------------------------------...

-25x^6 + 120x^4  - 144x^2 + 100  <==after cancellations

This is the final answer except multiplying by -1 might be a good idea or rearranging so it doesn't begin w/a negative. I can't find any factoring to further reduce it.