I need help pls, I'm in fourth grade and I don't know this :((( pls pls help

What is the rate of change of a line that passes through (2,-5) and (6,-2)?

Hilary decided to purchase 3 points in order to lower her interest rate on her $140,000 mortgage. how much additional money does she need to bring to closing? a. $4200 b. $4000 c. $6 d. $400

Abank manager wants to encourage new customers to open accounts with principals of at least $2,500. he decides to make a poster advertising a simple interest rate of 3%. what must the principal be if the bank manager also wants to advertise that one can earn $10 the first month? can the poster correctly say, "open an account of $2 comma 500 and earn at least $10 interest in 1 month! "?