Solution
= Solution
For an experiment beginning by mixing unbound <enzyme> with <substrate>, take $\boxed{[E](0)=e_0>0,\ [S](0)=s_0>0,\ [X](0)=[Y](0)=[E_i](0)=[P](0)=0}$. The <enzyme-substrate complexes>, inactivated enzyme and product are initially absent. Nonzero pre-existing product could be allowed without changing the dynamics here, since it has no feedback reaction in the specified scheme.