Number times Recurring Part of Reciprocal gives 9-Repdigit/Examples/37

Proof
Let $x = \dfrac 1 {37} = 0 \cdotp \dot 0 2 \dot 7$.

Then $n = 37$; $m = 27$ and $d = 3$

Therefore:
 * $27 \times 37 = 10^3 - 1$