一道七年级期末测试题x的平方+y的平方=2x+y-四分之五,求xy除以x+y 请写明过程.
2019-05-05
一道七年级期末测试题
x的平方+y的平方=2x+y-四分之五,求xy除以x+y
请写明过程.
优质解答
x^2+y^2=2x+y-5/4
x^2-2x+y^2-y+5/4=0
x^2-2x+1+y^2-y+1/4=0
(x-1)^2+(y-1/2)^2=0
x=1,y=1/2
x^2+y^2=2x+y-5/4
x^2-2x+y^2-y+5/4=0
x^2-2x+1+y^2-y+1/4=0
(x-1)^2+(y-1/2)^2=0
x=1,y=1/2