## Elementary Technical Mathematics

$2x+3y=9$ $2x+3y-2x=9-2x$ $3y=9-2x$ $3y\div3=(9-2x)\div3$ $y=3-\frac{2}{3}x$ if $x=3$ $y=3-\frac{2}{3}(3)=3-2=1$ if $x=0$ $y=3-\frac{2}{3}(0)=3-0=3$ if $x=-3$ $y=3-\frac{2}{3}(-3)=3-(-2)=3+2=5$