Find the remainder when a polynomial is divided by a linear expression (e.g., x - a or x + a), typically using the Remainder Theorem by direct substitution.
For a natural number $n$, let $a _ { n }$ be the remainder when the polynomial $2 x ^ { 2 } - 3 x + 1$ is divided by $x - n$. Find the value of $\sum _ { n = 1 } ^ { 7 } \left( a _ { n } - n ^ { 2 } + n \right)$. [3 points]
The polynomial $P ( x ) = ( x + 1 ) + ( x + 2 ) + \ldots + ( x + 9 )$ $$Q ( x ) = ( x + 1 ) + ( x + 2 ) + \ldots + ( x + 5 )$$ is divided by the polynomial. What is the remainder obtained from this division? A) 10 B) 12 C) 14 D) 16 E) 18