A system does 591 kJ of work and loses 256 kJ of heat to the surroundings. What is the change in internal energy, AE, of the system? Note that internal energy is symbolized as AU in some sources.

Idid the calculation and i get 875,000,000 which can be written as 8.75 x 10^6?

Okay well gravitational energy is matter forced by gravity making energy though the kinetic energy then the electric energy produces electricity from the kinetic energy and the kinetic energy gets its energy from the gravitational energy. was that the answer you wanted or something else?