Answer:
(x^2+4y^2+xy)(x^2+4y^2-xy)
Step-by-step explanation:
since both terms are perfect squares this can be factorised using the difference of squares formula a^2-b^2=(a+b)(a-b)
where a=x^2+4y and b=xy
therefore, the factorised form will be
(x^2+4y^2+xy)(x^2+4y^2-xy)
