1) the equation is:
[tex]2y+x=4[/tex]So we can rewrite the equation as a slope intercept so:
[tex]\begin{gathered} 2y=-x+4 \\ y=-\frac{1}{2}x+2 \end{gathered}[/tex]So the slope is -1/2
2) the equation is:
[tex]3x-2y=5[/tex]Now we evaluete the coordinates to see which one is not on the line so for (1,-1)
[tex]\begin{gathered} 3(1)-2(-1)=5 \\ 3+2=5 \\ 5=5 \end{gathered}[/tex]So is on the line
for (-1,-4)
[tex]\begin{gathered} 3(-1)-2(-4)=5 \\ -3+8=5 \\ 5=5 \end{gathered}[/tex]So it is on the line
for (3,2)
[tex]\begin{gathered} 3(3)-2(2)=5 \\ 9-4=5 \\ 5=5 \end{gathered}[/tex]So it is on the line
Finally for (1,2)
[tex]\begin{gathered} 3(1)-2(2)=5 \\ 3-4=5 \\ -1\ne5 \end{gathered}[/tex]So (1,2) is not on the line
3) if the slope is -2 and goes to the point (3,-1) we can use the equation of a line to find the intercept so:
[tex]\begin{gathered} y=-2x+b \\ -1=-2(3)+b \\ -1=-6+b \\ -1+6=b \\ 5=b \end{gathered}[/tex]So the intercept is 5 so the equation is:
[tex]y=-2x+5[/tex]