To find the y-intercept, we can convert this to slope-intercept form, or replace the value of x with 0 and solve for y.
We'll do both first.
-x + 5y = 45
5y = 45
Divide both sides by 5.
y = 9
Now let's convert it to slope-intercept.
-x + 5y = 45
Add x to both sides.
5y = 45 + x
Divide both sides by 5.
y = 1/5x + 9
y = 9
The y-intercept of our line is 9.
