У^2+3y=y-6y-9
y^2+3y-y+6y+9=0
Y^2+8y+9=0
121-(11-9x)²=121-(121-198х+81х²)=121-121+198х-81х²=198х-81х²=9х(22-9х)
(3x - y)(9x^2 + 3xy + y^2) = (3x)^3 - y^3 = 27x^3 - y^3
(3x - y + 2)^2 = (3x - y + 2)(3x - y + 2) = 9x^2 - 3xy + 6x - 3xy - y^2 - 2y +
+ 6x - 2y + 4 = 9x^2 - 6xy + 12x - y^2 - 4y + 4