Question

Solve:$x+3y=6:2x-3y=12$.

Answer 1

$x+3y=6$ .........$\left(1\right)$

$2x-3y=12$ ..........$\left(2\right)$

Adding equations $\left(1\right)$ and $\left(2\right)$ we get

$x+3y+2x-3y=6+12$

$\Rightarrow 3x=18$

$\Rightarrow x=\frac{18}{3}=6$

Put $x=6$ in $\left(1\right)$ we get

$x+3y=6$

$\Rightarrow 6+3y=6$

$\therefore 3y=0$ or $y=0$

$\therefore x=6,y=0$