Answer
16 kJ
Work Step by Step
∆E = q+w where q is the heat and w is the work.
As heat is absorbed q is positive and is equal to 45 kJ. But work is done by the system. So it is negative and the value of w is equal to -29 kJ.
Then, ∆E= 45 kJ-29 kJ = 16 kJ
