If there are two songs written and the longest one is 126 seconds less than twice the length of the short song, and the longest one lasts 286 seconds, then the shorter song's length can be found using this formula:
2x-126=286.
This would then turn into x-63=143 to show the time difference. Solving here for x, would be 206 seconds.
Answer:

Step-by-step explanation:
I supposed that is a "n".
Steps as below:

I think 53.088 is the answer
Answer: The required values are
x = 12 units, ST = 60 units and SU = 120 units.
Step-by-step explanation: Given that T is the midpoint of SU, where
ST = 5x and TU = 3x + 24.
We are to find the values of x, ST and SU.
Since T is the midpoint of SU, so we get

So, the value of x is 12.
Therefore,

and

Thus, the required values are
x = 12 units, ST = 60 units and SU = 120 units.