Which relation is a function?

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?

Write an inequality for this sentence the quotient of a number and -5 increased by 4 is at most 8

Provide all steps given to find the answer. simplify: 5(2x+9)²