3x + 8 + 4x - 9
O12x + 17
O7x-1
O7x+ 17

Answer:
7x - 1
Step-by-step explanation:
3x + 8 + 4x - 9 = ?
3x + 4x = 7x
8 - 9 = -1
3x + 8 + 4x - 9 = 7x - 1