To solve the equation \(-\frac{x}{2.9} = -3\), you can start by eliminating the negative sign on both sides:
\[ \frac{x}{2.9} = 3 \]
Next, multiply both sides by \(2.9\):
\[ x = 3 \times 2.9 \]
Calculating the right side:
\[ x = 8.7 \]
Thus, the solution to the equation is \(x = 8.7\).