Answer:
aₙ = 11 - 9(n - 1)
Step-by-step explanation:
2 - 11 = (-7) - 2 = -9
So it is an arithmetic sequence
a₁ = 11
a₂ = 2 = 11 + (-9) = 11 + (2 - 1)*(-9)
a₃ = -7 = 2 + (-9) = 11 + (-9) + (-9) = 11 + (3 - 1)*(-9)
.....
aₙ = 11 + (n - 1) * (-9)
or
aₙ = 11 - 9(n - 1)
