Well, if we don’t know Q1, Q2, Q3, Q4 and Q5 there is basically 8 variables for 5 equations so, it’s unsolvable.

My question actually was what information do we have on Q1, Q2, Q3, Q4 and Q5 (I know they aren’t equal to 0 because it will lead to T1 = T5 and that’s absurd and assuming Q1 = Q2 = Q3 = Q4 = Q5 ≠ 0 will lead to T2 = (4T1 +T5)/5 =358 K the real value being 354,25 K).

PS: what’s bothering the most is that they say “given all the values” meaning they are useful but assuming Q1 = Q2 = Q3 = Q4 = Q5 we don’t need the actual value of kA/L and the same statement with the method T = T(x) = ax + b

Best,

Karim