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    Hi,

    I have tried to do questions 7 & 9 but I am really stuck on them since I am getting them wrong.
    Answer for question 7
    x=2/3, y=1/3. Or x=1/3, y=2/3
    Answer for question 9
    (6, -6); tangent
    I have attached the questions and my workings

    Thanks!
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    (Original post by musicangel)
    Hi,

    I have tried to do questions 7 & 9 but I am really stuck on them since I am getting them wrong.
    Answer for question 7
    x=2/3, y=1/3. Or x=1/3, y=2/3
    Answer for question 9
    (6, -6); tangent
    I have attached the questions and my workings

    Thanks!
    For Q7 write y in terms of x using the linear equation. Yoy should get y= 3x/4 -13
    Then put that back into the equation of the circle. So where you see a y term in the circle equation - replace it with 3x/4 -13
    Then expand the brackets and use the quadratic formula to solve for x. Then find the corresponding y values for each x value found. Do the same with the next question. Write y in terms of x in the linear equation - by just dividing everything by 4. Then substitute that y value (in terms of x) into the equation of the circle. Then expand the brackets and form a quadratic equation =0
    Then use the quadratic formula to solve for x. Then find the corresponding y value. You should notice that there is only value for the point of intersection. This means that the line is tangent to the circle - by definition a tangent will only intersect a circle at one point
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    (Original post by musicangel)
    Hi,

    I have tried to do questions 7 & 9 but I am really stuck on them since I am getting them wrong.
    Answer for question 7
    x=2/3, y=1/3. Or x=1/3, y=2/3
    Answer for question 9
    (6, -6); tangent
    I have attached the questions and my workings

    Thanks!
    For question 7, try to write the other equation in terms of x and y first so like x^2 +something xy + y^2. You can multiply through by 2 to get rid of the fractions. Then substitute in your value for y (y=1-x). It comes out as a quadratic which you can then solve using the quadratic formula. Hopefully that makes sense. I have done the question using this method and I got the answers you gave there Also, don't forget to substitute your x-values back into the equation to get the y-values

    I'm still trying question 9 on my own first, but will let you know once I have figured out a method
 
 
 
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