2x+y=4 x+2y=5 x+y等于?2x+y=4x+2y=5x+y等于?

2x+y=4 x+2y=5 x+y等于?2x+y=4x+2y=5x+y等于? y*y*y*y+2x*x*x*x=4x*x*y 求x等于几,y等于几,写出所有选项! x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 4x+5y=105,2x+3y=178,x,y等于 已知x、y满足y²=-x²+2x-5/4-y,代数式xy/x+y等于多少 3x-2y等于75 3y-2x等于5 x=?Y=? x:2=y:4,则x:y等于 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 已知整数x y 满足 x的平方-2x+y的平方+4y=--5则x y 是x y 分别等于多少 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 x*x+2x+y*y-4y+5=0 x= y= 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 9x+8y=-2,4x+5y=-11,y最后等于多少 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 设x大于1,y大于0,x^y+x^-y=2根号二,x^y-x^-y等于? 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*y)的值 实数X,Y满足X大于等于Y大于等于1和2X平方-xy-5x+y+4=o,则x+y的值