Solve: 3(2x+y)=7xy and 3(x+3y)=11xy
3(2x+y)=7xy —(i)
3(x+3y)=11xy —(ii)
From Equation (i) we get,
$3(2x + y) = 7xy$
$\Rightarrow 6x + 3y = 7xy$
$\Rightarrow \frac{6x + 3y}{xy} = 7$
$\Rightarrow \frac{6{\mathrm{x}}}{{\mathrm{xy}}} + \frac{3{\mathrm{y}}}{{\mathrm{xy}}} = 7$
$\Rightarrow \frac{6}{{\mathrm{y}}} + \frac{3}{{\mathrm{x}}} = 7$ —-(iii)
From Equation (ii) we get,
$3(x + 3y) = 11xy$
$\Rightarrow 3x + 9y = 11xy$
$\Rightarrow \frac{3x + 9y}{xy} = 11$
$\Rightarrow \frac{3x}{xy} + \frac{9y}{xy} = 11$
$\Rightarrow \frac{3}{y} + \frac{9}{x} = 11$ —-(iv)
Multiplying Equation (iv) by 2 we get,
$\Rightarrow \frac{6}{y} + \frac{18}{x} = 22$ —-(v)
Now Subtracting Equation (iii) from Equation (v) we get,
$\Rightarrow \frac{6}{y} + \frac{18}{x} – \frac{6}{{\mathrm{y}}} – \frac{3}{{\mathrm{x}}}$=22-7
$\Rightarrow \frac{18}{x} – \frac{3}{x} = 15$
$\Rightarrow \frac{15}{x} = 15$
$\Rightarrow x = \frac{15}{15}$
$\Rightarrow {\mathrm{x}} = 1$
Substituting the value of x in equation (i) we get,
3(2x+y)=7xy
⟹ 6x+3y=7xy
⟹ 6(1)+3y=7(1)y
⟹ 6+3y=7y
⟹ 6=7y-3y
⟹ 4y=6
⟹ y = $\frac{6}{4}$
⟹ y=$\frac{3}{2}$
Therefore Required Solutions are x = 1 and y =$\frac{3}{2}$