Can someone please help me with this math problem? Thanks.

Answer:
x=23
Step-by-step explanation:
All four sides add up to 136, so subtract 4 and 4. This leaves 128. Divide that by 2 for the remaining sides, and that is 64 per side. Set 3x-5 equal to 64.
3x-5=64
+5 +5
3x=69
/3 /3
x=23.