Find x if eg is a median of triangle def.. 5x-17 & 3x+1

Write two subtraction equations that are equivalent to 5 + 12 = 17.

Your friend uses c=50p to find the total cost, c, for the people, p, entering a local amusement park what is the unit rate and what does it represent in the context of the situation?

Having a hard time understanding this question (see attachment).