(2x-3)(2x+3)-4(x-2)(x+2)

COROANA


Răspuns :

4x²-4(x²-4)=4x²-4x²+16=16
(4x^2 -9) -4(x^2 -4)
=4x^2 -9 -4x^2 +16
= -9+16 = 7