1. create an equation --- 101 = n+15+3n
2. simplify (combine like terms) --- 101= 4n+15
3. subtract 15 from both sides (101-15 = 4n+15-15) --- 86=4n
4. divide both sides by 4 (86/4=4n/4) --- 21.5 = n
therefor, n = 21.5
to check the equation just plug in 21.5 for n and it should equal 101