Why does the total amount of energy before and after any energy transformations remain the same?

answer : Because energy cannot be created or destroyed, the total input is equal to the total output. The total amount of energy remains the same even though it may change forms.

The amount of energy before and after any energy transformations remain the same because energy cannot be created or destroyed. From the law conservation of energy; any time energy is transferred between two objects, or converted from one form into another, no energy is created and none is destroyed. The total amount of energy involved in the process remains the same.