sequence and series arithmetic (1 Viewer)

[shell.q]

term7= 20
term13=38
find the common difference and the first term.
solve simultaneous right?
if anyone can give me the first few steps with the working out would be much aprecciated please =]

 

[Bacchus]

term7= 20
term13=38
find the common difference and the first term.
solve simultaneous right?
if anyone can give me the first few steps with the working out would be much aprecciated please =]

7th term: a + 6d = 20
13th term: a + 12d = 38

6d = 18
d = 3
a = 2