Concept:
Orthogonal circles condition:
\[
2(g_1g_2 + f_1f_2) = c_1 + c_2
\]
Step 1: Compare equations.
First circle:
\[
g_1=-4, f_1=-3
\]
Second:
\[
g_2=0, f_2=-1
\]
Step 2: Apply condition.
\[
2((-4)(0)+(-3)(-1)) = c+d
\]
\[
2(3) = c+d
\]
\[
c+d=6
\]