An electric charfe of -3 C is moved from a position where the electric potential is 1 V to a position where the electric potential is -6V. What is the chsange in potential energy of the charge with this change in position?

I know that change in
PE = k(q1q)/r_2 - k(q1q)/r_1

I am having trouble figuring out what the distance or r would be for this problem.

Potential difference is 5 volts.

Potential energy difference is 5Q, and Q is given.