On a number line what is the distance between 7,4 and it's opposites

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

Find the solution of this system of equation -7x+y=-20 9x-3y=36

Maria walks a round trip of 0.75 mile to school every day.how many miles will she walk in 4.5 days