In the following equations, what would you multiply the second equation to eliminate the "x"? *(PLEASE I REALLY NEED HELP!! D:)

3x + y = 20
x + y = 12

1) -1

2) 1

3) -3

4) 3

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?