(x+y)(x+y-10)+25=0,且x-y=3,求x,y

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(x+y)(x+y-10)+25=0,且x-y=3,求x,y(x+y)(x+y-10)+25=0,且x-y=3,求x,y(x+y)(x+y-10)+25=0,且x-y=3,求x,y因为:(x+y)(x

(x+y)(x+y-10)+25=0,且x-y=3,求x,y
(x+y)(x+y-10)+25=0,且x-y=3,求x,y

(x+y)(x+y-10)+25=0,且x-y=3,求x,y
因为:(x+y)(x+y-10)+25=0,所以:(x+y)^2-10(x+y)+25=0
即:(x+y-5)^=0,所以:x+y=5
因为:x-y=3,联立方程组,解得:x=4,y=1

由x-y=3, x=y+3代入(x+y)(x+y-10)+25=0,
得:(2y+3)(2y+3-10)+25=0
4y^2+12y+9-20y-30+25=0
4y^2-8y+4=0
y^2-2y+1-0 (y-1)^2=0 y=1 x=4