Respuesta :

Equation A simplifies to 0 = 0. It is always true.

Equation B simplifies to 1 = -1 for a ≠ 0. It is never true.

Equation C simplifies to 2a = 0. It is true only for a = 0.

Equation D simplifies to 2a = 0. It is only true for a = 0.

The equation that is true for all values of "a" is ...
  A. Equation A