w = 925 J , work is done on the system.
Work Step by Step
Given, $\Delta U$= 510 J; q = -415 J ( negative sign for exothermic process). We know, $\Delta U$ = q+w or w= $\Delta U$-q = 510 J-(-415 J)= 925 J. Sign is positive which indicates that the work is done on the system.