Given an arithmetic sequence in the table below, create the explicit formula and list any restrictions to the domain.

So the numbers are increasing by adding 7.

B is the correct answer because you add 7 from 40

a(n) = 40 + 7(n - 1)

for example... 
If you want 5th term,
a(5) = 40 + 7(5 - 1)
40 + 28 = 68.

1. 0.3 •4 is the same as 4 groups of 0.32. 7•0.8 is the same as 7 groups of 0.83. it increases by 0.5 every time, so 0.5x4 it increases by 0.9 every time, so 0.9x5. 0.9•12=10.86. 0.47•5=2.35i can finish the next ones in a separate post