Question

упростите выражение (х+у) (х-у)-(х*2+3у*2)

Answer 1

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

Answer 2

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