Answer:
see explanation
Step-by-step explanation:
The n th term of an arithmetic sequence is
[tex]a_{n}[/tex] = a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Here a₁ = 40 ( first row )
d = - 4 ( 4 fewer than the row below ), thus
[tex]a_{n}[/tex] = 40 - 4(n - 1) = 40 - 4n + 4 = 44 - 4n
That is
[tex]a_{n}[/tex] = 44 - 4n
(b)
a₁₀ = 44 - 4(10) = 44 - 40 = 4
There are 4 boxes on the 10 th row
