Answer:
17-5n
Step-by-step explanation:
i believe it is asking for the nth term(english is my third language, i learnt this in italian, sorry if it's not what the question means)
the formula:
a(n) = a + d(n−1)
a(n)= nth term
a= first term
d= common difference
a(n) = a + d(n−1)
a(n)= 12+(-5)(n-1)
a(n)= 12-5(n-1)
a(n)=12-5n+5
a(n)=17-5n
