The basic equation for modeling radioactive decay is

dx/dt = - rx

where x is the amount of radioactive substance at time t and r is the decay rate.Some radioactive substances decay into other radioactive substances, which in turn also decay.For example, Strontium 92 (r₁ = 0.256/hour) decays into Yttrium 92 (r₂ = 0.127/hour) which in turn decays into Zirconium.Write down a pair of equations for Strontium and Yttrium to describe what is happening.

Starting at t = 0 with 5 x 10²⁶ atoms of Strontium 92 and none of Yttrium, t = 8 hours in steps of 1/3 hour. Use the Runge-Kutta (ode23) method for the same problem and compare your results.