if a3 = 20 and a6=41 for an arithmetic sequence, find a1

1 answer

a(6)=a(1)+(6-1)d
a(3)=a(1)+(3-1)d
Subtract:
a(6)-a(3)=3d
41-20=3d
d=7

from which
a(3)=a(1)+(3-1)7
a(1)=20-14=6
Similar Questions
  1. Question 1Create your own arithmetic sequence. List at least six terms of your sequence. Explain what makes it arithmetic. State
    1. answers icon 1 answer
    1. answers icon 1 answer
    1. answers icon 1 answer
  2. QuestionClassify the following list of numbers as an arithmetic sequence, a geometric sequence, some other sequence, or not a
    1. answers icon 1 answer
more similar questions