Question 456489
y^8 - 256
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View it as the difference of 2 squares.
{{{a^2 - b^2 = (a-b)*(a+b)}}}
{{{y^8 - 256 = (y^4)^2 - 16^2}}}
 = {{{(y^4 - 16)*(y^4 + 16)}}}
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Then do the same for {{{y^4 - 16}}}