Slope-intercept form uses the following formula:
y = mx + b
In this case, "m" is the slope of the line and "b" is the y-intercept. We'll now restate the equation found in the question above:
y = -5x + 1
We can now see that a value of (-5) is in the "m" position while a value of (1) is in the "b" position. Therefore, we can determine that the slope of the line is (-5) and the y-intercept is (1).
I hope this helps!