I need help with this please!!

The table represents a linear function. what is the slope of the function? –6 –4 4 6

What is best way to getting answer for my exam is

Dakota earned $7.50 in interest in account a and $18.75 in interest in account b after 15 months. if the simple interest rate is 4% for account a and 5% for account b, which account has the greater principal? explain. to make it a little easier, there is an image. good luck!