Answer:
[tex]a_{12}[/tex] = 34.5
Step-by-step explanation:
The n th term of an arithmetic sequence is
[tex]a_{n}[/tex] = a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Given [tex]a_{70}[/tex] = 121.5, then
a₁ + (69 × 1.5) = 121.5
a₁ + 103.5 = 121.5 ( subtract 103.5 from both sides )
a₁ = 18
Hence
[tex]a_{12}[/tex] = 18 + (11 × 1.5) = 18 + 16.5 = 34.5
Answer:
12th term = 34.5
Step-by-step explanation:
l = a + (n-1)*d
d = 1.5
70th term = 121.5
a + 69 * 1.5 = 121.5
a + 103.5 = 121.5
a = 121.5 - 103.5
a = 18
12 th term = 18 + 11 * 1.5 = 18 + 16.5 = 34.5
