Question 436578
Think: "difference of squares"
.
{{{a^4-b^4}}}
can be rewritten as:
{{{(a^2)^2-(b^2)^2}}}
which factors out as:
{{{(a^2-b^2)(a^2+b^2)}}}
but, you're still not done. The term on the left is another "difference of squares":
{{{(a-b)(a+b)(a^2+b^2)}}}