#### Answer

$(2\frac{2}{5},7\frac{1}{5})$

#### Work Step by Step

$2x+y=12$
$y=3x$
Substitute 3x for y in the first equation.
$2x+3x=12$ $\longrightarrow$ simplify
$5x=12$ $\longrightarrow$ divide both sides by 5
$5x\div5=12\div5$ $\longrightarrow$ simplify
$x=2\frac{2}{5}$
Substitute $2\frac{2}{5}$ for x in the second equation.
$y=3(2\frac{2}{5})$
$y=7\frac{1}{5}$