Sunday
March 26, 2017

Post a New Question

Posted by on .

if 6 times the sixth term is equal to 15 times the fifteenth term ,find its 21st term

  • arithmetic sequence - ,

    6(a+5d) = 15(a+14d)
    6a + 30d = 15a + 210d
    9a = -180d
    a = -20d

    a + 20d = -20d + 20d = 0

  • arithmetic - ,

    24

Answer This Question

First Name:
School Subject:
Answer:

Related Questions

More Related Questions

Post a New Question