Answer
Write $-3)\overline{\text{2 0 -5 1}}$
Work Step by Step
The first step is to write the numerical coefficients of the dividend in decreasing degree inside the division symbol, then write the value of $c$ outside the symbol.
The coefficients of the dividend are: $2, 0, -5, 1$ (there is no $x^2$ term so the coefficient is $0$).
To solve for $c$, equate $x+3$ to $0$ then solve for $x$:
$x+3=0
\\x=-3$
Thus, the first step in the synthetic division is to write:
$-3)\overline{\text{2 0 -5 1}}$