Asked by Vanvan
Find the 1st term if the 4th term of the arithmetic sequence is 24 and the 12nd term is 56
Answers
Answered by
Bosnian
an = a ( n - 1 ) d
where
a = first term
d = common difference
a4 = a + 3 d = 24
a12 = a + 11 d = 56
Now solve system:
a + 3 d = 24
a + 11 d = 56
The solution is:
a = 12 , d = 4
The 1st term = 12
where
a = first term
d = common difference
a4 = a + 3 d = 24
a12 = a + 11 d = 56
Now solve system:
a + 3 d = 24
a + 11 d = 56
The solution is:
a = 12 , d = 4
The 1st term = 12