To solve the equation \( d^2 - 42d = 0 \), we can factor it:
\[ d(d - 42) = 0 \]
Setting each factor equal to zero gives us:
- \( d = 0 \)
- \( d - 42 = 0 \) → \( d = 42 \)
Thus, the solutions are:
\[ d = 0, 42 \]
So, the final answer is:
\[ d = 0, 42 \]