Answer
$NH_4NO_3(s)\rightarrow N_2O(g)+2H_2O(g)$
This is decomposition.
Work Step by Step
$NH_4NO_3(s)\rightarrow N_2O(g)+H_2O(g)$
Add a coefficient of 2 to $H_2O$ to balance $H$.
$NH_4NO_3(s)\rightarrow N_2O(g)+2H_2O(g)$
This is a decomposition reaction because a compound is breaking down into simpler compounds.
