x^2-3;
=x²-(√3)²
=(x+√3)(x-√3)
4a^2-7;
=(2a)²-(√7)²
=(2a+√7)(2a-√7)
x^4-4;
=(x²)²-2²
=(x²+2)(x²-2)
=(x²+2)(x+√2)(x-√2)
16b^2-11
=(4b)²-(√11)²
=(4b+√11)(4b-√11)