Answer:

Step-by-step explanation:
Given
--- initial
-- rate
Value after a year = $20.70
Required
Expression to calculate its value after y years
This is calculated using:

Where

Substitute
in 



Substitute
and
in 

Answer:
1/3
Step-by-step explanation:
1) 1/6+1/6= 2/6
2) 2 and 6 can both be divide be 2.
2/2=1 and 6/2=3
Associative Property of Multiplication
Because the grouping is the only things that changes