Respuesta :

1st term a₁ = - 3.7; common difference d = - 1.3

the nth term a(n) = a₁ +(n-1)d  or a(n) = 3.7 + (n-1)(-1.3)

a(n) = - 3.7 - 1.3n  + 1.3 ====> -2.4 - 1.3.n   Or as per your answer:
a(n) = -1.3.n - 2.4