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
[tex]y = \frac{x {}^{2} }{4} - 3x + c[/tex]
