Question:
Find the real values of x and y for which:
$\frac{(x+3 i)}{(2+i y)}=(1-i)$
Solution:
Given:
$\frac{x+3 i}{2+i y}=(1-i)$
$\Rightarrow x+3 i=(1-i)(2+i y)$
$\Rightarrow x+3 i=1(2+i y)-i(2+i y)$
$\Rightarrow x+3 i=2+i y-2 i-i^{2} y$
$\Rightarrow x+3 i=2+i(y-2)-(-1) y\left[i^{2}=-1\right]$
$\Rightarrow x+3 i=2+i(y-2)+y$
$\Rightarrow x+3 i=(2+y)+i(y-2)$
Comparing the real parts, we get
$x=2+y$
$\Rightarrow x-y=2 \ldots$ (i)
Comparing the imaginary parts, we get
$3=y-2$
$\Rightarrow y=3+2$
$\Rightarrow y=5$
Putting the value of y = 5 in eq. (i), we get
$x-5=2$
$\Rightarrow x=2+5$
$\Rightarrow x=7$
Hence, the value of x = 7 and y = 5