¿ cuantas sillas tiene el teatro?
The number of chairs in each row is represented by the sequence
The total number of chairs is then represented by the series
Since and , then the number of chairs in each row is represented by an arithmetic sequence with a first term of and a a common difference of .
The total number of chairs will then be found using the partial arithmetic sum formula . It is given that the theater has rows so . To use this formula when , you must then find .
The nnth term of an arithmetic sequence is . Therefore:
The total number of chairs is then:
Partial sum formula.
The theater then has chairs.