Final answer:
The store's sales grow according to the recursive rule Pn=Pn-1 + 15. 
a) P1 is 55, 
b) P2 is 70, 
c) the explicit formula is Pn = 40 + 15n.
d) The predicted sales in 10 years is 190.
Step-by-step explanation:
a) To calculate P1, we substitute the value of n-1 in the recursive rule. 
Therefore, P1 = P0 + 15
= 40 + 15 
= 55.
b) To calculate P2, we substitute the value of n-1 in the recursive rule. 
Therefore, P2 = P1 + 15 
= 55 + 15 
= 70.
c) The explicit formula for the line is Pn = P0 + 15n. 
In this case, Pn = 40 + 15n.
d) To predict the store's sales in 10 years, we substitute the value of n in the explicit formula. 
Therefore, P10 = 40 + 15(10) 
= 40 +150 
= 190.