The first thing you should know is that the slope of a perpendicular line is the opposite reciprocal. So, the slope of line j is 1/5. This is your current equation: y=1/5x + b. Plug in your coordinate to the equation, it should look like this: 9=1/5(5)+ b. 1/5 times 5 equals 1, so this is what it should look like: 9=1 + b. Subtract 1 from both sides to get 8 = b. Go back to your original equation and plug in 8 to b. This is your final equation: y = 1/5x + 8. Hope this helped!
