Question

a 2.85 m long pendulum has a 5.60 kg bob. The bob is pulled to the right and given a push back towards its rest position so that when the bob passes through its rest position, its kinetic energy is 85 J. If when the pendulum bob passes through a position that is at a distance of d m to the rights of its rest position, it has a kinetic energy of 35 J. The value of d is?