Answer
(1,-2)
Work Step by Step
$15x+3y=9$
$y=-2x$
Substitute -2x for y in the first equation.
$15x+3(-2x)=9$ $\longrightarrow$ simplify
$9x=9$ $\longrightarrow$ divide both sides by 9
$9x\div9=9\div9$ $\longrightarrow$ simplify
$x=1$
Substitute 1 for x in the second equation.
$y=-2(1)$ $\longrightarrow$ simplify
$y=-2$
