Help pls. I'm confuseddd

If f(x)= 3x+6 which of the following is the inverse of f(x)

The parabola y = x² - 4 opens: a.) up b.) down c.) right d.) left

Without multiplying, tell which product is larger and why. 5 × 1/3 or 5 × 2/3 a)5 × 1/3 because 1/3 is less than 2/3 b) 5 × 1/3 because 1/3 is greater than 2/3 c) 5 × 2/3 because 1/3 is less than 23 d) 5 × 23 because 1/3 is greater than 2/3