Answer
See answer below.
Work Step by Step
a) $CuS$ is insoluble.
$Cu^{2+}(aq)+S^{2-}(aq)\rightarrow CuS(s)$
b) $CaCO_3$ is insoluble.
$Ca^{2+}(aq)+CO_3^{2-}(aq)\rightarrow CaCO_3(s)$
c) $AgI$ is insoluble.
$Ag^{+}(aq)+I^{-}(aq)\rightarrow AgI(s)$
