What is -7 as a fraction and explain plss

—the graph shows how fast a strand of human hair grows. how many inches would the hair have grown in 5 months

Do not comment if you aren’t going to . create a real-life situation and create a system and show how it might be modeled algebraically with a system of equations (or inequalities) show all work include a few sentences explaining the situation, your variables of choice and what each represents, and how you would set it up and solve it algebraically. !

What is the best way to answer questions with a x expression in the question. for example 3x + 10x=?