Answer
$y=-\frac{1}{2}x+\frac{3}{2}$
Work Step by Step
$(2, \frac{1}{2}), (\frac{1}{2}, \frac{5}{4})$
$y-\frac{1}{2}=\frac{\frac{5}{4}-\frac{1}{2}}{\frac{1}{2}-2} \times(x-2)$
$y=-\frac{1}{2}(x-2)+\frac{1}{2}$
$y= -\frac{1}{2}x +\frac{3}{2}$