Answer:
-5
Step-by-step explanation:
First, put the equation into the form y = mx +b (where m is the slope and b is the y-intercept)
This would look like:
[tex]5x + y = 3\\y = -5x + 3[/tex]
This means the slope is -5.
Parallel lines always have the same slope, so the slope of the parallel line is also -5
