\({36x^3 - 64x}\)
i know that this is a difference of squares... but i'm not sure how can i get the textbook answer of \({4x(3x +4)(3x -4)}\)? i got \({x(6x - 8)(6x + 8)}\) isn't that the same thing? and please show step by step!
Factor the following:
36 x^3 - 64 x
Factor common terms out of 36 x^3 - 64 x.
Factor 4 x out of 36 x^3 - 64 x:
4 x (9 x^2 - 16)
Express 9 x^2 - 16 as a difference of squares.
9 x^2 - 16 = (3 x)^2 - 4^2:
4 x (3 x)^2 - 4^2
Factor the difference of two squares. (3 x)^2 - 4^2 = (3 x - 4) (3 x + 4):
4 x (3 x - 4) (3 x + 4)
+118608 YES yours is the same thing BUT yours is not fully factored.
You can factor 2 out of each of the brackets and then you will get the text book answer.
Yours is not wrong, it is just not finished. 
This is a good question becasue you are obviously trying to understand.
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