What is 7 minus f in algebraic expression

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?

Rewrite so the subject can be y in the formula d=m-y/y+n

Aof 12 , we to a of 4 to on a .of 4 be ?