if the 4th term of an arithmetic sequence is 24 and the 12th term is 56,what is the 28th term?
So many of these same type of problems!
term4 = a + 3d = 24
term12 = a + 11d = 56
subtract:
8d = 32
d = 4
then a + 12 = 24
a = 12
use the same definition I just used to find term28