Well first your going to halve to get it in graphing material.
5y-15=5x
First: Add 15 on both sides of the equal sign
You will get: 5y= 5x+15
Remember: Your y has to always be by it's self for order you to graph
Next: You will divide everything by 5 so you'll be able to get your y alone
You will get: y= x+3
To graph: You must know which ones are your intercepts
Y- intercept: 3
X- intercept: 1
First: You will plot your y on the graph then you will rise 1 and run 1 < keep doing that to create a line
HOPE THIS HELPS! ^_^