# Thread: Another solving question

1. ## Another solving question

Hi
Can someone tell me how i can solve the following:

1)Solve $x+iy=(2y+1)+(x-7)i$ for real values x and y.
This is what i have done:
$x+iy=2y+1+ix-7i$
$7i-1=y(2+i)+x(i-1)$

2)Solve $2x+(y+4)i=(3+2i)(2-i)$ for real values x and y.

P.S

2. Originally Posted by Paymemoney
Hi
Can someone tell me how i can solve the following:

1)Solve $x+iy=(2y+1)+(x-7)i$ for real values x and y.
This is what i have done:
$x+iy=2y+1+ix-7i$
$7i-1=y(2+i)+x(i-1)$

2)Solve $2x+(y+4)i=(3+2i)(2-i)$ for real values x and y.

P.S
1. $x + iy = (2y + 1) + (x - 7)i$.

Equating real and imaginary parts gives:

$x = 2y + 1$
$y = x - 7$.

Solve these equations simultaneously.

2. $2x + (y + 4)i = (3 + 2i)(2 - i)$

$2x + (y + 4)i = 6 - 3i + 4i - 2i^2$

$2x + (y + 4)i = 6 + i + 2$

$2x + (y + 4)i = 8 + i$.

Equating real and imaginary parts:

$2x = 8$
$y + 4 = 1$.

Solve these equations.

3. Originally Posted by Paymemoney
Hi
Can someone tell me how i can solve the following:

1)Solve $x+iy=(2y+1)+(x-7)i$ for real values x and y.
This is what i have done:
$x+iy=2y+1+ix-7i$ Mr F says: Now equate real and imaginary parts:

x = 2y + 1 .... (1)
y = x - 7 .... (2)

Solve the above equations simultaneously.

[snip]

2)Solve $2x+(y+4)i=(3+2i)(2-i)$ for real values x and y.

P.S
For 2) expand the right hand side and then use the same approach as 1).