Question

(x-y)(x+y)+2(3x-2y)+5 разложите на множмтели​

Answer 1

$(x-y)(x+y)+2(3x-2y)+5=x^2-y^2+6x-4y+5=$

$=x^2+6x+9-y^2-4y-4=(x^2+6x+9)-(y^2+4y+4)=$

$=(x+3)^2-(y+2)^2=(x+3+y+2)(x+3-y-2)=(x+y+5)(x-y+1)$