『4x+9y=97 5x+5y=65』
已知X.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值
(5x+3y)(3y-5x)-(4x-y)(4y+x)=
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
已知:4x = 5y,求(x+y) :y
x-y+5x-4x= ?
4x+5y=34 5x+4y=65 则x+y= x-y=多少
已知x*x+4x+y*y-2y+5=0,则x*x+y*y=?
x+y=5; x^y+y^x=17
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
数学题……555{(3x+y)(3x-y)-(x-5y)(5x-y)-(x-2y)²÷(-4x),x=-2.y