3x+y+4x+y+1
3x + y + 4x + y + 1
Rearrange the terms: 3x + 4x + y + y + 1
Group the like terms: (3x + 4x) + (y + y) + 1
Simplify the like terms: 7x + 2y + 1
You can't add unlike terms, so this is the answer.