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    Could anyone help me with this question?


    Show that the circles with equations x² + y² - 6x + 4y –23 = 0 and
    x² + y² - 22x – 8y + 121 = 0 touch each other and find the coordinates of their common point.

    Thanks! Any help would be appreciated as I have my exam tomorrow.
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    (Original post by *hedgehog*)
    Could anyone help me with this question?


    Show that the circles with equations x² + y² - 6x + 4y –23 = 0 and
    x² + y² - 22x – 8y + 121 = 0 touch each other and find the coordinates of their common point.

    Thanks! Any help would be appreciated as I have my exam tomorrow.
    x² + y² - 6x + 4y –23 = x² + y² - 22x – 8y + 121
    -6x+4y-23=-22x-8y+121
    16x+12y=121+23, put this equation back into one of the circle equations and solve for x or y, then hence find coordinates.
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    (Original post by *hedgehog*)
    Could anyone help me with this question?


    Show that the circles with equations x² + y² - 6x + 4y –23 = 0 and
    x² + y² - 22x – 8y + 121 = 0 touch each other and find the coordinates of their common point.

    Thanks! Any help would be appreciated as I have my exam tomorrow.
    x² + y² - 6x + 4y –23 = x² + y² - 22x – 8y + 121

    Solve to find y in terms of x, then sub back into one of the equations and show there is only one solution.
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    cheers!
 
 
 
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