求图~(1)x^2-y^2≤0 (2)(x+2y-1)(x-y+3)>0
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
若|x+y-1|+(x-y-2)²=0,求代数式(x+2y)(x-2y)-(2x-y)(-y-2x)的值.
已知:3x=8y.求(1)x+y/y (2)2x+3y/x-2y
已知x-y=1,y≠0,求{(x+2y)²+(2x+y)(x+4y)-3(x+y)(x-y)}÷y的值.
已知x,y满足约束条件x-y-1≤0,(x-2)^2+y^2≤1,求Z=2x-3y的最小值
已知|x+y+2|+(2x-3y-1)²=0 求 ⑴x、y的值 ⑵2x³-x²-3y
已知2x-y+1的绝对值+ (3x+2分之3y)平方=0,求代数式x+y分之y的平方除以(x-y分之x-1)(x-x-y
已知2x+3y=2(x>0,y>0),求x+y最大值
求导数y=3x-x^2 求y',y'/ x=1 y'/x=0
2x²-3xy=y²=0(x,y不得o)求x/y+y/x
已知|2x-3y|+|3x-y-1|=0,求x,y的值.
设实数x,y满足{x-y-2≤0 x+2y-5≥0 y-2≤0.(1)求z=x+y的取值范围;(2)求u=(x+y)/x