Answer
$a_{1}=195$
$a_{n}=195-7n+7=202-7n$
Work Step by Step
$a_{n}=a+\left( n-1\right) d;a_{m}=a+\left( m-1\right) d\Rightarrow a_{n}-a_{m}=\left( n-m\right) d$
$a_{12}-a_{8}=\left( 12-8\right) \times d=118-146=-28\Rightarrow d=-7$
$a_{8}-a_{1}=\left( 8-1\right) \times d\Rightarrow 146-a_{1}=7\times \left( -7\right) \Rightarrow a_{1}=195$
$a_{n}-a_{1}=\left( n-1\right) d\Rightarrow a_{n}-195=\left( n-1\right) \times \left( -7\right) \Rightarrow a_{n}=195-7n+7=202-7n$
