Question

Разложите на множители:
1-x^2+2xy-y^2

Answer 1

=1-(x-y)^2 = (1-(x-y))*(1+(x-y)) = (1-x+y)*(1+x-y)

Answer 2

$1-x^2+2xy-y^2=1 - (x^2-2xy+y^2)=1-(x-y)^2=\\=(1-x+y)(1+x-y)$