Need on numbers 17/18 i don't know how to do them

What are two numbers that have a sum of 15

On friday, there were x students at the baseball game. on monday, there were half as many students at the game as there were on friday. on wednesday, there were 32 fewer students at the game as there were on friday. which expression could represent the total number of tickets sold for all 3 games?

Elm street is straight. willard's house is at point h between the school at point s and the mall at point m. if sh = 3 miles and hm = 4.5 miles, what is the value of sm in miles?