Question

What is the first term of an arithmetic sequence with a common difference of -7 and a seventh term of 40

Answer 1

\[a_n = a+d(n-1) \]
an= term value = 40
d = -7
n = 7
a = first term

Answer 2

an=a+(n-1)d
40=a+(7-1)(-7)
40=a-42
82=a.
an is the term you want to know
a is the first term
n is the term number
d is the difference

Answer 3

i mean an is "any term" so in this case its the seventh term number