|x+2|+(y+3)²=0可以得出
X=-2,Y=-3
5x²-3y²-(x²-y²)-(3x²+4y²)=-50把它化简5x²-3y²-(x²-y²)-(3x²+4y²)要过程5x²-3y²-(x²-y²)-(3x²+4y²)=5x²-3y²-x²+y²-3x²-y²=x²-6y²=4-54=-50