The formula deltaPE=-qE(deltaX) indicates that when a charge moves in the direction of the electric field, its potential energy decreases, resulting in a negative change in potential energy. Specifically, if the electric field points to the right and a positive charge also moves to the right, the field does work on the charge, reducing its potential energy. This negative change in potential energy reflects energy conservation principles. The discussion clarifies that assuming a positive charge simplifies the analysis of the formula. Overall, the interaction between the electric field and the charge leads to a decrease in potential energy as the charge moves in the field's direction.