已知x(x-1)-(x^2-y)=2,求代数式3x^2+3y^2/2-3xy

问题描述:

已知x(x-1)-(x^2-y)=2,求代数式3x^2+3y^2/2-3xy

x(x-1)-(x^2-y)=2,
变为y=x+2,
∴3x^2+3y^2/2-3xy=3x^+(3/2)(x+2)^-3x(x+2)
=(3/2)x^+6.