Answer :
[tex]\begin{gathered} y=mx+\text{b } \\ \text{where} \\ m=\text{slope} \\ b=y-\text{intercept} \end{gathered}[/tex][tex]\begin{gathered} 1=-\frac{1}{2}(4)+b \\ 1=-2+b \\ b=1+2 \\ b=3 \end{gathered}[/tex][tex]y=-\frac{1}{2}x+3[/tex]