Write an explicit formula for the sequence 8,3,-2,-7,-12 ... then find a14

This is an arithmetic progression with common difference, d = - 5 and first term, a=8

Tn = a + (n-1) d

Tn = 8 + (n-1) * - 5

Tn = 8+-5 (n-1)

Tn = 8-5n+5

Explicit Formula: Tn = - 5n+13

a14 = - 5 (14) + 13

= - 70+13

= - 57