一道简单方程:x+y-3=0 (x-2)^2+(y-1)^2=20/3x=2+(根号10)/3,y=1-根号10/3还是x=(2+根号10)/3,y=1-根号10/3
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![一道简单方程:x+y-3=0 (x-2)^2+(y-1)^2=20/3x=2+(根号10)/3,y=1-根号10/3还是x=(2+根号10)/3,y=1-根号10/3](/uploads/image/z/12874619-11-9.jpg?t=%E4%B8%80%E9%81%93%E7%AE%80%E5%8D%95%E6%96%B9%E7%A8%8B%3Ax%2By-3%3D0+%EF%BC%88x-2%29%5E2%2B%28y-1%29%5E2%3D20%2F3x%3D2%2B%EF%BC%88%E6%A0%B9%E5%8F%B710%EF%BC%89%2F3%EF%BC%8Cy%3D1-%E6%A0%B9%E5%8F%B710%2F3%E8%BF%98%E6%98%AFx%3D%EF%BC%882%2B%E6%A0%B9%E5%8F%B710%EF%BC%89%2F3%EF%BC%8Cy%3D1-%E6%A0%B9%E5%8F%B710%2F3)
一道简单方程:x+y-3=0 (x-2)^2+(y-1)^2=20/3x=2+(根号10)/3,y=1-根号10/3还是x=(2+根号10)/3,y=1-根号10/3
一道简单方程
:x+y-3=0
(x-2)^2+(y-1)^2=20/3
x=2+(根号10)/3,y=1-根号10/3
还是x=(2+根号10)/3,y=1-根号10/3
一道简单方程:x+y-3=0 (x-2)^2+(y-1)^2=20/3x=2+(根号10)/3,y=1-根号10/3还是x=(2+根号10)/3,y=1-根号10/3
由x+y-3=0 得:(x-2)=-(y-1)
代入(x-2)^2+(y-1)^2=20/3得:
2(x-2)^2=20/3
2(y-1)^2=20/3
∴x=2+根号10/3,y=1-根号10/3
x=2-根号10/3,y=1+根号10/3
x+y-3=0可得x=3-y带入方程即可解得
x+y-3=0①
(x-2)^2+(y-1)^2=20/3②
由①得:
x=3-y③
把③代入②,得
(3-2-y)(3-2-y)+(y-1)(y-1)=20/3
(1-y)(1-y)+(y-1)(y-1)=20/3
1-2y+y²+y²-2y+...
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x+y-3=0①
(x-2)^2+(y-1)^2=20/3②
由①得:
x=3-y③
把③代入②,得
(3-2-y)(3-2-y)+(y-1)(y-1)=20/3
(1-y)(1-y)+(y-1)(y-1)=20/3
1-2y+y²+y²-2y+1=20/3
2+2y²-4y=20/3
6+6y²-12y=20
6y²-12y=14
……
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