Question
Solve the following simultaneous equation.
$\frac{27}{x-2}+\frac{31}{y+3}=85 ; \frac{31}{x-2}+\frac{27}{y+3}=89$

Answer

$\frac{27}{x-2}+\frac{31}{y+3}=85$
$\frac{31}{x-2}+\frac{27}{y+3}=89$
Let $\frac{1}{x-2}=m \text { and } \frac{1}{y+3}=n$
$27 m+31 n=85 \ldots$
$31 m+27 n=89 \ldots$
Adding both equations
$58 m+58 n=174$
Dividing both sides by $58$
$m + n =3$
Subtracting Eq. $I$ and $II$
$27 m+31 n=85$
$-31 m-27 n=-89$
$-4 m+4 n=-4$
Dividing both sides by $4$
$- m + n =-1 \ldots( IV )$
Equating Eq. $III$ and $IV$
$m + n =3$
$\frac{- m + n =-1}{2 n =2}$
$n =\frac{2}{2}$
$n =1$
Subsituting $n=1$ in Eq. $III$
$m +1=3$
$m=3-1$
$m=2$
$\therefore m =\frac{1}{ x -2} \Rightarrow \frac{1}{ x -2}=2 \Rightarrow 2( x -2)=1 \Rightarrow 2 x -4=1 \Rightarrow 2 x =4+1$
$\Rightarrow 2 x =5 \Rightarrow x =\frac{5}{2}$
$\therefore n =\frac{1}{ y +3} \Rightarrow \frac{1}{ y +3}=1 \Rightarrow y +3=1 \Rightarrow y =1-3 \Rightarrow y =-2$
$y =2$
Hence $(x, y)=\left(\frac{5}{2},-2\right)$

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