Help plz choose the correct equation for the function whose graph is shown

The table above shows approximate conversions from gallons to liters. what is the value of x?

Pepe and leo deposits money into their savings account at the end of the month the table shows the account balances. if there pattern of savings continue and neither earns interest nor withdraw any of the money , how will the balance compare after a very long time ?

The measures of the legs of a right triangle are 15m and 20m . what is the length of the hypotenuse