What is the explicit formula for the arithmetic sequence - 7.5, - 9, - 10.5, - 12 ...

= - 1.5n - 6

Step-by-step explanation:

Given that the sequence is arithmetic with n th term (explicit formula

= a₁ + (n - 1) d

where a₁ is the first term and d the common difference

Here a₁ = - 7.5 and d = - 9 - ( - 7.5) = - 9 + 7.5 = - 1.5

= - 7.5 - 1.5 (n - 1) = - 7.5 - 1.5n + 1.5 = - 1.5n - 6