In three different experiments, the following results were obtained for the reaction
A -> products:
[A]o = 1.00M, t1/2=50 min ;
[A]o = 2.00M, t1/2 = 25 min;
[A]o = 0.50M, t1/2 = 100 min.
Write the rate equation for this reaction, and indicate the value of K?