## Elementary Technical Mathematics

$4x+3y=-2$ $x+y=0\longrightarrow$ solve for y by subtracting x from both sides $x+y-x=0-x$ $y=-x$ Substitute -x for y in the first equation. $4x+3(-x)=-2\longrightarrow$ simplify $4x-3x=-2\longrightarrow$ simplify $x=-2$ Substitute -2 for x in the second equation. $y=-(-2)\longrightarrow$ simplify $y=2$