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    the real and imaginary parts of the complex number z = x + iy satisfy the equation (2-i)x - (1 + 3i)y - 7 =0

    a) find the value of x and y
    b) find the values of i) modulus of z ii) argz

    how would i go about starting this question?

    will rep - i'm just really confuddled

    jb
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    (Original post by jumblebumble)
    the real and imaginary parts of the complex number z = x + iy satisfy the equation (2-i)x - (1 + 3i)y - 7 =0

    a) find the value of x and y
    b) find the values of i) modulus of z ii) argz

    how would i go about starting this question?

    will rep - i'm just really confuddled

    jb
    Equate for real and imaginary numbers.

    So to start you off:
    z=x+iy so x=real and y=imaginary

    2x-y=x (1)
    -x-3=y (2)

    so simplify:

    y=x (1)
    y=-x-3 (2)

    so sub y into (2) and y=-y-3 therefore y=-1.5 etc...
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    (Original post by JTeighty)
    Equate for real and imaginary numbers.

    So to start you off:
    z=x+iy so x=real and y=imaginary

    2x-y=x (1)
    -x-3=y (2)

    so simplify:

    y=x (1)
    y=-x-3 (2)

    so sub y into (2) and y=-y-3 therefore y=-1.5 etc...
    the answers are x=3 and y=-1? :/
    but thankyou anyway. jb
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    JTeighty's method is right, it's just that he's written the equations down wrong.

    Start with:

    2x-y-7=0

    -3-3y=0

    And solve as simultaneous equations.

    (Expanding out, Re(0) and Im(0))

    (Also, is the second part ok?)
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    (Original post by Scallym)
    JTeighty's method is right, it's just that he's written the equations down wrong.

    Start with:

    2x-y-7=0

    -3-3y=0

    And solve as simultaneous equations.

    (Expanding out, Re(0) and Im(0))

    (Also, is the second part ok?)
    Sorry, I wasn't concentrating properly. It's actually quite embarrasing that I'm doing F maths and despite that, i got those simple equations wrong. :'(
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    (Original post by JTeighty)
    Sorry, I wasn't concentrating properly. It's actually quite embarrasing that I'm doing F maths and despite that, i got those simple equations wrong. :'(
    That wasn't meant to be a criticism, sorry. I do it annoyingly often.:p:
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    (Original post by Scallym)
    That wasn't meant to be a criticism, sorry. I do it annoyingly often.:p:
    Don't worry, I didn't take it badly. I was just stating my stupidity.
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    Seems I'm too late. =)
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    (Original post by jumblebumble)
    the real and imaginary parts of the complex number z = x + iy satisfy the equation (2-i)x - (1 + 3i)y - 7 =0

    a) find the value of x and y
    b) find the values of i) modulus of z ii) argz

    how would i go about starting this question?

    will rep - i'm just really confuddled

    jb
    Just out of interest, is this FP1 or FP2?
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    (Original post by JTeighty)
    Just out of interest, is this FP1 or FP2?
    This is FP1
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    (Original post by Longorefisher)
    This is FP1
    Thanks.
 
 
 
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