Formula use:
a^3+b^3=\left(a+b\right)\left(a^2-ab+b^2\right)
Explanation
Given expression is: x^6+y^6
Factorize
x^6+y^6
\rightarrow\left(x^2\right)^3+\left(y^2\right)^3
\rightarrow\left(x^2+y^2\right)\{\left(x^2\right)^2-x^2.y^2+\left(y^2\right)^2\}
\therefore\left(x^2+y^2\right)\left(x^4-x^2y^2+y^4\right)
Ans: \left(x^2+y^2\right)\left(x^4-x^2y^2+y^4\right)