Question

Сколько будет (x+y)(x-y)-(x^2+3y^2)

Answer 1

(x+y)(x-y)-(x²+3y²)=(x²-y²)-(x²+3y²)=x²-y²-x²-3y²=-4y²

Answer 2

(x+y)(x-y)-(x^2+3y^2)
x^2-y^2-x^2+3y^2
-y^2+3y^2
2y^2
Вроде так