The two equations would be: \(c= w+9.9\) (as the weather in Calgary is 9.9 degrees warmer than Winnipeg) and \(-15.5= w+c\) (as the sum of the two temperatures is -15.5 degrees)
We already have the C value (\(C= w+9.9\)) so we can plug that into the other equation, as \(-15.5= w+ (w+9.9)\), which would be: \(-15.5=2w+9.9\) simplified,
then \(-25.4= 2w\) and finally \(w=-12.7\).
Putting that value into the other equation as \(-15.5= -12.7+ c,\ -15.5 + 12.7= -2.8,\) therefore \(c= 2.8\)
Answer: \(w= -12.7 c=-2.8\)