Hi there!
Here are all the steps into solving this equation for "r" :
-2r - 8 + = -5r + 12
Add 5r to each side of the equation
-2r + 5r - 8 = 12
Add 8 to each side of the equation
-2r + 5r = 20
3r = 20
Divide each side of the equation by 3
r = 6.6666...
There you go! I really hope this helped, if there's anything just let me know! :)