SOLUTION: 1) In an arithmetic sequence, a4=8 and a7=26. Find a1 and d. Write the first 5 terms of the sequence. 2) find the sum 3) find the sum 4) Find the first 5) Fi

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: 1) In an arithmetic sequence, a4=8 and a7=26. Find a1 and d. Write the first 5 terms of the sequence. 2) find the sum 3) find the sum 4) Find the first 5) Fi      Log On


   

Question 1138516: 1) In an arithmetic sequence, a4=8 and a7=26. Find a1 and d. Write the first 5 terms of the sequence.

2) find the sum

3) find the sum

4) Find the first

5) Find a7


Found 2 solutions by mananth, ikleyn:
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
In an Arithmetic sequence
A[n]= a+(n-1)d
a4=8 =a+3d................................1
a7=26=a+6d..............................2
solve 1 &2
subtract 1 from 2
6d-3d = 18
3d=18
d= 6
a+3d =8
a+3(6)=8
a=-10
First five terms -10,-4,2,8,14



Answer by ikleyn(52776) About Me  (Show Source):
You can put this solution on YOUR website!
.

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