## Elementary Technical Mathematics

$5x+2y=1$ $y=-3x$ Substitute -3x for y in the first equation. $5x+2(-3x)=1\longrightarrow$ simplify $5x-6x=1\longrightarrow$ simplify $-1x=1\longrightarrow$ divide both sides by -1 $-1x\div-1=1\div-1\longrightarrow$ simplify $x=-1$ Substitute -1 for x in the second equation. $y=-3(-1)\longrightarrow$ simplify $y=3$