Hi i need help on where i have gone wrong in the following equations:

1)Solve for real values x and y.

x=1 or x=-3

2)Solve for real values x and y.

Also another question does and

P.S

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- January 18th 2010, 02:54 PMPaymemoneySolving another equation
Hi i need help on where i have gone wrong in the following equations:

1)Solve for real values x and y.

x=1 or x=-3

2)Solve for real values x and y.

Also another question does and

P.S - January 18th 2010, 03:09 PMCalculus26
For 2

a complex number z = 0 if and only if Re(z) = 0 and Im(z) =0

(x^2 - y^2) + i (2xy -18) = 0

x^2 = y^2 x =__+__y

and 2xy = 18

If x= y 2x^2 = 18 x=__+__3

If x = -y -2x^2 =18 and there are no solutions

only solutions are (3,3) and (-3,-3)

For 1)

(x+2i)(x-2i) = x^2 + 2ix - 2ix - 4i^2 = x^2 + 4

also

Even if http://www.mathhelpforum.com/math-he...8dca7823-1.gif

how do you conclude 4x+12 = 9 -x^2 ?

you should have x^2 + 4 = 5 -12 i

x^2 = 1-12i

if x is real x^2 must be real so there are no solutions

yes i^2 =-1 and -i^2 = 1