in general if your method achieves the correct answer 100% of the time in which it is able to be applied, then it should be accepted. Being able to devise your own methods of solving problems is in and of itself a sign of mastery of a concept.

furthermore it seems that your method is algebraically equivillent to the "standard method"

D(A + B +C) = E = DA +DB +DC
if that makes any sense

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