So what you'd do is use the equation: y-y1=m(x-x1)
Using that equation, plug in your values for m.
y-y1=6/5(x-x1)
Then, plug in the points (25, 9) in their respective places.
y-9=6/5(x-25)
Then, distribute the slope through the parenthesis; multiply 6/5 by x and -25 respectively.
So, y-9=6/5x-30
Then, solve for y by adding the 9 to the other side of the equation.
So, y=6/5x-21
And that should be your equation for the line.