In Questions Solve the Recurrence Relation Either by Using the Characteristic

Short Answer

In questions solve the recurrence relation either by using the characteristic equation or by discovering
a pattern formed by the terms.
- $$a _ { n } = - 10 a _ { n - 1 } - 21 a _ { n - 2 } , \quad a _ { 0 } = 2 , a _ { 1 } = 1$$