Practice problem
If an arithmetic sequence is described by the explicit formula an=18n−200a_{n} = 18n-200an=18n−200, find the value of a1+a2a_1 + a_2a1+a2.
−182-182−182
−346-346−346
−164-164−164
−18-18−18
Type a concept, like “slope” or “photosynthesis”.