已知x,y满足X2 -3x+4y=7,试求3x+4y的最大值?

已知x,y满足X2 -3x+4y=7,试求3x+4y的最大值? 已知实数x、y满足2x2-7xy+3y2=0,求x：y 已知实数x,y满足x2+y2=14x+6y+6那么3x+4y的最大值 已知x.y满足X2-y2=2xy.则x-y/x+y=?x. 已知实数x,y满足x2+y2+4x+3=0,求(y-2)/(x-1)的值域. 已知实数x,y满足x2+y2+2x-4y+5=0 已知实数x,y满足x2+y2=4,求x+y的取值范围 已知实数xy满足x2-x+y=3则x+y的最大值是 已知X和Y满足3X+4Y=2,X-Y-1/7 已知实数x、y满足X2+y2-xy+2x-y+1=0,试求x、y的值 已知实数x、y满足X2+y2-xy+2x-y+1=0,试求x、y的值 已知实数x、y满足x2+4y2=2x+4y-2,求x-2y的平方根. 已知:实数x、y满足x2+y2-4x-6y+13=0则y的x次方= 已知实数x,y满足x2+3x+y-3=0,则x+y的最大值为_____ 已知实数x,y满足x2+3x+y-3=0,求x+y的最大值 已知实数x,y满足X2+3X+Y-3=0,则x+y的最大值是. 已知实数X,Y,满足X2+3X+ Y-3=0,则X+ Y的最大值为多少 已知实数X,Y满足X2+3X+2Y-3=0,则X+Y的最大值是