Question

Simplify:
$0.2x+0.3y=1.3$
$0.4x+0.5y=2.3$

Answer 1

$0.2x+0.3y=1.3$

$(0.2x+0.3y)10=1.3\times 10$

$\Rightarrow 2x+3y=\mathrm{13...}\left(1\right)$

$0.4x+0.5y=2.3$

$(0.4x+0.5y)5=2.3\times 5$

$2x+2.5y=\mathrm{11.5...}\left(2\right)$

Equation $\left(1\right)$ & $\left(2\right)$

$2x+3y-2x-2.5y=13-11.5$.

$\Rightarrow 0.5y=1.5$

$\Rightarrow 5y=15$

$\Rightarrow y=\frac{15}{5}=3$

$x=(13-\frac{3y}{2})$

$=(13-\frac{3.3}{2})$

$\Rightarrow$$\frac{13-9}{2}=\frac{4}{2}=2$

$\therefore x=2;y=3$