How would you describe in factor notation the present worth of a cash flow that gives you $10 in periods zero through 20, then in period 21 gives you $8, in period 22 gives $6, and so on, until period 24 when you recieve $2. 

P = 10(P\A,i,25)(1+i) - 2(P\G,i, 5)/(1+i)^19

P = 10(P\A,i,21)(1+i) - 2(P\G,i, 5)/(1+i)^19

P = 10(P\A,i,25)(1+i) - 8(P\G,i, 5)/(1+i)^19

P = 10(P\A,i,25)(1+i) - 2(P\G,i, 5)