Question

( a² + b² - 4c²)² - 4a²b²

Answer 1

use formula,
x² - y ² =( x - y)(x + y)

now,
(a² + b² -4c²)= x ( let )
2ab = y ( let)

x² - y² = (x -y)(x + y)
so,

(a² +b² -4c²-2ab)(a² +b² -4c²+2ab)

={(a²-2ab+b²)-4c²}{(a²+b²+2ab)-4c²}

={(a-b)²-(2c)²}{(a+b)²-(2c)²}

=(a-b-2c)(a-b+2c)(a+b-2c)(a+b+2c)

Answer 2

Answer:

(a-b-2c) (a-b+2c) (a+b-2c) (a+b+2c)