Formula - y = mx + b
Slope(m) = 1/2
Y-Intercept(b) = -5
To graph you always start with the y-intercept. So you would go down (since it is negative) 5 and then you would go up 1 ( since it is positive) and right 2 and you just keep going up 1 and right 2.
Hope this Helps and makes sense!!