the answer is below [tex] \frac{dy}{dx} = \frac{1}{2} (x - 6)[/tex] multiply both sides by dx
[tex]dy = \frac{1}{2} (x - 6)dx[/tex] integrate both sides of the diffrential
[tex]integral \: dy = integral \: \frac{1}{2} (x - 6)dx[/tex] simplify and integrate to get y alone don't forget to tack on c with your indefinite integral
