Does anyone understand this

Write a function for a rotation 90 degrees counter clockwise about the origin, point 0

James is playing his favorite game at the arcade. after playing the game 3 times, he has 8 tokens remaining. he initially had 20 tokens, and the game costs the same number of tokens each time. the number t of tokens james has is a function of g, the number of games he plays. write the function’s formula? t=

What is the approximate mark up percentage rate before m equals $1740 marked up from p equals $19,422