How can i find the circumference of a circle with only the diameter given?

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

If c(x) = 4x – 2 and d(x) = x2 + 5x, what is (cxd)(x)

Arefrigeration system at your company uses temperature sensors fixed to read celsius (°c) values, but the system operators in your control room understand only the fahrenheit scale. you have been asked to make a fahrenheit (°f) label for the high temperature alarm, which is set to ring whenever the system temperature rises above –10°c. what fahrenheit value should you write on the label?