Question

(x-3y)(x+3y)-x(3x-y)+(3y-x)^

Answer 1

(x-3y)(x+3y)-x(3x-y)+(3y-x)^2 =

= x² - 9y² - 3x² + xy + 9y² - 6xy +x² =

= - x² - 5xy = -x·(x +5y)

Answer 2

(x-3y)(x+3y)-x(3x-y)+(3y-x)^2=
=x^2-9y^2-3x^2+xy+9y^2-6xy+x^2 =
=-x^2-5xy=-x*(x+5y);