x + 4y = n and 5x - 2y = 10
If we let x = 0 in the second equation, the y intercept is at (0, -5)
Then, subbing these values into the first equation for x and y we have that (0) + 4(-5) = n = -20
The graph here confirms this : https://www.desmos.com/calculator/dcugsajo7a