(a) Given plane: $3 x-4 y+12 z-3=0$
Given point $(0,0,0) \quad \therefore d=\left|\frac{a x_1+b y_1+c z_1+d}{\sqrt{a^2+b^2+c^2}}\right|$
$$
d=\left|\frac{3(0)-4(0)+12(0)-3}{\sqrt{3^2+(-4)^2+12^2}}\right|=\frac{3}{13}
$$
(b) The point is $(3,-2,1)$, the plane
$$
\begin{aligned}
&2 x-y+2 z+3=0 \\
&\therefore \quad d=\left|\frac{2 \cdot 3-(-2)+2 \cdot 1+3}{\sqrt{2^2+(-1)^2+2^2}}\right|=\frac{13}{8}
\end{aligned}
$$
(c) Given plane : $x+2 y-2 z-9=0$ and point $(2,3,-5)$
$d=\frac{|2+2 \times 3-2(-5)-9|}{\sqrt{1^2+2^2+(-2)^2}}=3$.
(d) Given point $(-6,0,0)$ and plane
$$
\begin{aligned}
&2 x-3 y+6 z-2=0 \\
&d=\frac{|2(-6)-3(0)+6(0)-2|}{\sqrt{2^2+(-3)^2+6^2}}=2 .
\end{aligned}
$$