Question

Quanto devo subtrair de (2/3)^-1 para obter (1/7)^0?

Answer 1

    (2/3)⁻¹ = 3/2
    (1/7)⁰ = 1

  3/2 -  x = 1
          -x = 1 - 3/2
           x = 3/2 - 1 
           x = 3/2 - 2/2
           x = 1/2 <-- devo subtrair 1/2

Verificando:
     3/2 - 1/2 = 2/2 = 1