Question 248206
{{{ 0.3x-0.2y=4 }}}
{{{ 0.5x+0.5y=45/23}}}
First step, multiply boths sides by 10. 
1.{{{ 3x-2y=40}}}
2.{{{ 5x+5y=450/23}}}
Multiply eq. 1 by 5 and eq. 2 by 2 and add them to eliminate y.
{{{15x-10y+10x+10y=200+900/23}}}
{{{25x=4600/23+900/23}}}
{{{25x=5500/23}}}
{{{x=220/23}}}
Now use either equation to solve for y.
{{{5x+5y=450/23}}}
{{{1100/23+5y=450/23}}}
{{{5y=-650/23}}}
{{{y=-130/23}}}