Because it has a slope of 5, we can already set up part of the equation:
y = 5x
Now, we need to find the y-intercept.
We can do that by subtracting 1 from the x value of the provided coordinate pair, and subtracting 5 from 9.
1 - 1 = 0
9 - 5 = 4
The y-intercept is 4.
Our equation is y = 5x + 4