No because I said so I didn’t even care what about the money that was
Answer:

Step-by-step explanation:
Given,
Art electives = 3,
History electives = 4,
Computer electives = 5,
Total number of electives = 3 + 4 + 5 = 12,
Since, if a student chooses an art elective and a history elective,
So, the total combination of choosing an art elective and a history elective = 
Also, the total combination of choosing any 2 subjects out of 12 subjects = 
Hence, the probability that a student chooses an art elective and a history elective = 

Which is the required expression.
Its very simple. Every triangle has a maximum degree of 180°.
We can substract all of the given angles to get our x angle, like so:
x = 180 -102 - 39 = 39°
If your wondering how much each pair costs individually then its 7.89 per pair