Answer:
Therefore the equation dor nth term is,
[tex]a_{n} =a_{1} + (n-1)\times d[/tex] and
[tex]a_{30} =-18[/tex]
Step-by-step explanation:
Given:
Arithmetic Sequence as
11 , 10 , 9 , 8 , ..........
∴ First term = a₁ = 11
Second term = a₂ = 10
∴ Common Difference = d = a₂ - a₁ = 10 - 11 = -1
∴ d = -1
To Find:
[tex]a_{n} = ?\\and\\a_{30} = ?[/tex]
Solution:
An equation for the nth term of the arithmetic sequence is given by
[tex]a_{n} =a_{1} + (n-1)\times d[/tex]
Substitute n= 30 for [tex]a_{30}[/tex] and a₁ and d we get
[tex]a_{30} =11 + (30-1)\times -1\\\\a_{30} =11+29\times -1\\\\a_{30} =11-29\\\\a_{30} =-18\\\\\therefore a_{30} =-18\ \textrm{as required}[/tex]
Therefore,
[tex]a_{30} =-18[/tex]
