How do you factor x^(4n) - y^(4n)x4n−y4n?
1 Answer
May 12, 2016
Explanation:
Note that both
x^(4n)=(x^(2n))^2x4n=(x2n)2 y^(4n)=(y^(2n))^2y4n=(y2n)2
With this knowledge, we will factor this expression as a difference of squares:
color(red)a^2-color(blue)b^2=(color(red)a+color(blue)b)(color(red)a-color(blue)b)a2−b2=(a+b)(a−b)
Thus, we see that
x^(4n)-y^(4n)x4n−y4n
=(color(red)(x^(2n)))^2-(color(blue)(y^(2n)))^2=(x2n)2−(y2n)2
=(color(red)(x^(2n))+color(blue)(y^(2n)))(color(red)(x^(2n))-color(blue)(y^(2n)))=(x2n+y2n)(x2n−y2n)
Notice that we can factor
x^(4n)-y^(4n)=(x^(2n)+y^(2n))(x^(2n)-y^(2n))x4n−y4n=(x2n+y2n)(x2n−y2n)
=(x^(2n)+y^(2n))((x^n)^2-(y^n)^2)=(x2n+y2n)((xn)2−(yn)2)
=(x^(2n)+y^(2n))(x^n+y^n)(x^n-y^n)=(x2n+y2n)(xn+yn)(xn−yn)