Question

Разложите на множители трехчлены:
$x^{4}-10x^{2}+9$
$</span>4x^{2}+3xy-y^{2}</span>$

Answer 1

$x^4-10x^2+9=x^4-9x^2-x^2+9=x^2(x^2-9)-(x^2-9)= \ =(x^2-9)(x^2-1)=(x-3)(x+3)(x-1)(x+1)$

$4x^2+3xy-y^2=4x^2+4xy-xy-y^2= \ =4x(x+y)-y(x+y)=(x+y)(4x-y)$