The length of a rectangular photo frame is x cm. The width of the frame is 65 cm shorter than 3 times its length. If the perimeter of the photo frame is 110 cm, what is the length?
Let L be the length of the frame.
The width is 3L - 65.
The perimeter of the frame is 2L + 2(3L - 65) = 2L + 6L - 130 = 8L - 130 cm.
Since the perimeter is 110 cm, then 8L - 130 = 110 cm.
Adding 130 to both sides, we get 8L = 240 cm.
Dividing both sides by 8, we get L = 30 cm. Answer: \boxed{30}.