Can someone tell me if these are correct?

What are the domain and range of the function? f(x) = -4 (sqrt)x

An initial investment of $100 is now valued at $150. the annual interest rate is 5%, compounded continuously. the equation 100e0.05t = 150 represents the situation, where t is the number of years the money has been invested. about how long has the money been invested? use your calculator and round to the nearest whole number. years

Kai walked one and two-thirds of a mile on saturday and four and one-sixth of a mile on sunday. how many miles did kai walk?