Remember that slope-intercept form is the following:
[tex]y = mx+ b[/tex]
Let's try to solve for that form.
[tex]-x + \dfrac{1}{2} y = -\dfrac{5}{2}[/tex]
[tex]\dfrac{1}{2} y = x - \dfrac{5}{2}[/tex]
[tex]y = 2x - 5[/tex]
The equation is y = 2x - 5.