Lexi wants to create an arithmetic sequence. She wants the 4th term to be 40 & t(5)=80. Is it possible to create an arithmetic sequence to fit her information? If it is possible, write the equation. If not, explain why not.

Answer 1

sure ...
term(4) = a + 3d = 40
term(8) = a + 7d = 80
subtract them:
4d = 40
d = 10
back in a+3d = 40 to find a
.....
take over.