Question

Factorise 81x^4 + 4y^4​

Answer 1

Answer:

81x⁴+4y⁴

= (81x⁴+4y⁴+36x²y²) -36x²y²

=(9x²+2y²) ²-(6xy) ²

using identity a²-b²=(a+b) (a-b)

=(9x²+2y²) ²-(6xy) ²=(9x²+2y²+6xy) (9x²+2y²-6xy)

Mark as Brainlist answer.