Question

Разложите на множители ; x^4-16x^2
-4x^2-8xy-4y^2

Answer 1

$x^4-16x^2=(x^2)^2-(4x)^2=(x^2-4x)(x^2+4x)$
$-4x^2-8xy-4y^2=-(4x^2+8xy+4y^2)=\=-((2x)^2+2*2x*2y+(2y)^2)=-((2x+2y)^2$