Very easy and simple and short

Which expression is equivalent to (9x - 3 1/ + 1 3/8)

What is the solution to the equation? k/6.4=8.7 2.3 5.568 15.1 55.68

The average daily maximum temperature for laura’s hometown can be modeled by the function f(x)=4.5sin(πx/6)+11.8 , where f(x) is the temperature in °c and x is the month. x = 0 corresponds to january.what is the average daily maximum temperature in may? round to the nearest tenth of a degree if needed.use 3.14 for π .