y∈R,x²+y²=2x+8,求x²+y²的最值
已知x、y是实数,且x²+y²-4x-6y+12=0.求x²+y²的最值,x-y
若|x+y-1|+(x-y-2)²=0,求代数式(x+2y)(x-2y)-(2x-y)(-y-2x)的值.
集合A={y|y=x²-1,x∈R},B={y|y=-2x²+2,x∈R},求A∩B
集合A{y|y=x²-1,x∈R},B{y|y=-2x²+2,x∈R}求A∩B
已知x,y的值满足方程组x+2y=3,x-y=-2,求x/(x-y)²+x²-y²/(x+
已知集合M={y|y=2^x,x∈R},集合N={y|y=x²,x∈R},求M∩N
x,y∈R ,3x+4y=1,求x²+y²的最小值
若x-y=6,xy=-8,求代数式(x+y+z)²+(x-y-z)(x-y+z)-2·z(x+y)的值
已知x² +y²+5/4=2x+y,求y-x的值
已知x²+4y²-6x+8y+13=0,求x-y/x+y的值.
已知y-2x=0,求3x²-2y²/(x+y)(x-y)的值
已知x+3y=2,求代数式(x²-y²/x+y)-【2(x+y)】的值