How to find the third side of a triangle if two sides are known?

What are the exclude value of mn+3m

Need ! the total ticket sales for a high school basketball game were $2,260. the ticket price for students were $2.25 less than the adult ticket price. the number of adult tickets sold was 230, and the number of student tickets sold was 180. what was the price of an adult ticket?

Joanie wrote a letter that was 1 1/4 pages long. katie wrote a letter that was 3/4 page shorter then joagies letter. how long was katies letter