已知x加5y减6等于0 则4的2x加y得次方乘8的y减x的次方等于多少-搜答案-拍题作业网

1/2再答：再问：谢谢了，问题解决了

x的平方-4x+y的平方+2y+5=x的平方-4x+4+y的平方+2y+1=(x-2)^2+(y+1)^2=0x-2=0x=2y+1=0y=-1x+y=2-1=1

再答：谢谢

X+Y=5,XY=2,5X+4Y-3X-2Y+XY=2X+2Y+XY=2(X+Y)+XY=2×5+2=12.

x^2+2x+y^2-6y+10=0=(x^2+2x+1)+(y^2-6y+9)=0=(x+1)^2+(y^2-6y+3^2)=0=(x+1)^2+(y-3)^2=0x=-1y=3xy=-3

再问：姐姐，你多大啦，再答：20再问：哦哦，你家在哪呀，你当我姐姐好不好，？再问：^ω^再问：姐姐，你不说话我就当你默认了哈，！哈哈，姐，！再答：O(∩_∩)O再答：姐姐现在比较忙哦再问：

x^2-2x+y^2+6y+10=0x^2-2x+1+y^2+6y+9=0(x-1)^2+(y+3)^2=0x-1=0,y+3=0x=1,y=-3(x-y)/(x+y)=4/(-2)=-2

3x^2+2xy+y^2-6x-6y+9=0(x+y)^2-6(x+y)+9=0(x+y-3)^2=0x+y=3

x^2+y^2+2x-4y+5=0,(x+1)^2+(y-2)^2=0,x=-1,y=2(-1)^2006-1/2=1-1/2=1/2

x²+y²+4x-6y+13=0(x+2)²+(y-3)²=0x+2=0、y-3=0x=-2、y=3

x+y-2=0x+y=2x²-y²=(x+y)(x-y)=6x-y=6/(x+y)=6/2=3x-y-5=3-5=-2

x的平方加y的平方加4x减2y加5等于0(x+2)^2+(y-1)^2=0x+2=0y-1=0x=-2y=1

7再答：要过程吗再问：不用再答：有好评吗

x²+y²-4x-2y+5=0x²-4x+4+y²-2y+1=0(x-2)²+(y-1)²=0x-2=0x=2y-1=0y=1√(x+y)/

问题求什么?再问：求x加y的值再答：x^2-2x+1+y^2-6y+9=0(x-1)^2+(y-3)^2=0x=1y=32x+3y=11

3x-6y-5=03（x-2y）=5x-2y=5/32x-4y+6=2（x-2y）+6=2×5/3+6=28/3或9又1/3

x^2+4x+y^2-2y+5=0(x^2+4x+4)+(y^2-2y+1)=0(x+2)^2+(y-1)^2=0x=-2,y=1x^2+y^2=(-2)^2+1^2=4+1=5

x²+y²+z²-2x-4y-6z+14=0(x-1)²+(y-2)²+(z-3)²=0因为每个平方数都≥0,它们之和为0,那么它们每个都为

x^2+y^2+2x-6y+10=0(x+1)^2+(y-3)^2=0所以x+1=0,y-3=0所以x=-1,y=3所以x+y=-1+3=2