Answer:
(16 + 3x)
Step-by-step explanation:
(16 + 3x)
You end up with this expression because you only know that the longer piece is 16 centimeters longer than 3 times the shorter piece. Since it's 16 cm longer, you are adding 16. You do three times the x value because it is three times the shorter piece. However, I may be wrong about this. It's my best guess though.