Answer:
Step-by-step explanation:
We can use the FOIL method to expand two multiplied binomials. It states that 
. The FOIL method stands for First(first terms) outer(outer terms) inner(inner terms) last(last terms).
So, we can expand our binomials now!
Start circle: πd = (3.14)(19) = 59.7
Move diagonally to the circle with the radius of 6.2.
Second circle: 2πr = 2(3.14)(6.2) = 39
Move upwards to the circle with the radius of 10.5
third circle: 2πr = 2(3.14)(10.5) = 66
Move right to the circle with the diameter of 16.6
Fourth circle: πd = (3.14)(16.6) = 52.2
Move down to the circle with the diameter of 7.7
fifth circle: πd = (3.14)(7.7) = 24.2
Move down to the circle with the diameter of 50
Sixth circle: πd = (3.14)(50) = 157.1
Move left to the circle with the radius of 11.8
Seventh circle: 2πr = 2(3.14)(11.8) = 74.1
Move down to the circle with the radius of 38
Eight circle: 2πr = 2(3.14)(38) = 238.8
Move right to the circle with the diameter of 1.1
ninth circle: πd = (3.14)(1.1) = 3.5
Move right to the circle with the radius of 14.8
10th circle = 2πr = 2(3.14)(14.8) = 93
Move up to the end.
Hope this helps :)
7-4=3
10-7=3
13-10=3
we can see that this is an arithmetic sequence with a difference of 3
the nth term=the first term +(n-1) times the difference
so a(n)=4+3(n-1)
