80 POINTS Which properties justify the steps taken to solve the system?

{2a+7b=03a−5b=31

Drag the answers into the boxes to match each step.

10a+35b=0; 21a−35b=217
​31a = 217
a = 7
2(7)+7b=0
14 + 7b = 0
7b=−14
b=−2

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?