Answer:
3x
Step-by-step explanation:
2y + 1 + x + ? = 2y + 1 + 4x
Subtract 2y from each side
2y -2y+ 1 + x + ? = 2y-2y + 1 + 4x
1 + x + ? = 1 + 4x
Subtract 1 from each side
1 -1+ x + ? = 1 -1+ 4x
x + ? = 4x
Subtract x from each side
x-x+? = 4x-x
? = 3x
