若(x-1\2)²+(2y+1)²=0.求x²+y²的值
若|x+y-1|+(x-y-2)²=0,求代数式(x+2y)(x-2y)-(2x-y)(-y-2x)的值.
(1)已知x+y=6,x²-y²=5,求x-y的值(2)若x+y=3,x²+y²
若x、y满足2x+y=6,x-3y=1,求7y(x-3y)²-2(3y-x)³的值
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
4/X+1/Y=2,XY=-1,求代数式4Y-X/X-2Y/(x+2y-12Y²/x-2y)的值
已知方程组2x+y=6 x-3y=1,求7y(x-3y)²-2(3y-x)³的值
已知|x+y+2|+(2x-3y-1)²=0 求 ⑴x、y的值 ⑵2x³-x²-3y
已知x²+x*y=-1,x*y+y²=2,试求2x²-x*y-3y²的值
当x=2,y=-1时,求代数式(x+y)(x-y)+(x-y)²-(x²-3xy)的值
若正数x,y满足x²-y²=2xy,求(x-y)/(x+y)的值
(1)已知x²+y²-2x+4y+5=0,求x、y的值
若(x+y)²-2x-2y+1=0,求(x+y)的999次方