Răspuns :
(x+2)^2-16x^2=( aplicam a^2 -b^2=(a-b)(a+b) ) =
=(x+2-4x)(x+2+4x)=
=(2-3x)(2+5x)
=(x+2-4x)(x+2+4x)=
=(2-3x)(2+5x)
(x+2)²-16x²=(x+2)(x+2)-16x²=x²+2x+2x+4-16x²=x²+4x+4-16x²=-15x²+4x+4=(2-3x)(2+5x)