Question:
Find the real values of x and y for which:
$(1-i) x+(1+i) y=1-3 i$
Solution:
$(1-i) x+(1+i) y=1-3 i$
$\Rightarrow x-i x+y+i y=1-3 i$
$\Rightarrow(x+y)-i(x-y)=1-3 i$
Comparing the real parts, we get
$x+y=1 \ldots(i)$
Comparing the imaginary parts, we get
$x-y=-3 \ldots$ (ii)
Solving eq. (i) and (ii) to find the value of x and y
Adding eq. (i) and (ii), we get
$x+y+x-y=1+(-3)$
$\Rightarrow 2 x=1-3$
$\Rightarrow 2 x=-2$
$\Rightarrow x=-1$
Putting the value of x = -1 in eq. (i), we get
$(-1)+y=1$
$\Rightarrow y=1+1$
$\Rightarrow y=2$