1. The problem statement, all variables and given/known data In an experiment, the isotope I-128 is created by bombarding I-127 with neutrons. This creates 1.5E6 I-128 atoms per second. Initially there are no I-128. The half-life of I-128 is 25 minutes. Find the equation that represents the number of I-128 atoms as a function of time. 2. Relevant equations dy/dt=creation rate-decay rate 3. The attempt at a solution I set up dy/dt=(1.5E6)t-ay. a is the decay rate in e^(-at), and y(t) is the number of I-128 after time t. I tried solving this as a first order linear equation and got a horriable answer. Where am I going wrong?