2x-5y=7 2x+3y=1 求x,y等于几

2x-5y=7 2x+3y=1 求x,y等于几 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! 求下列函数的反函数 y=2x-1等于几 y=1减x分之3等于几 y=5x-2分 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知2x^2+3y^2=4x^2y^2+1,x,y为正整数,求x^2+y^2等于几 2X+8Y=17,3X+5Y=7,X和Y,等于几? 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 y²+3x=7,y³+x=3,求y等于几. x方+y方-2x-4y+5=0 求(x-y)的1999次方等于几? (3x-5y)-(3x-2y)等于几 x+3=5-y,那么x+y等于几 2x等于5y,2z等于3y求3x等于几z