THE FIFTH TERM OF AN ARITHMETIC SEQUENCE IS 23 AND THE 12TH TERM IS 72.AND THEY SAY DETERMINE THE FIRST THREE TERMS OF THE SEQUENCE AND NTH TERM

Question

Reiny · Accepted Answer

you have to know the formula for the general term of an AS.

term(n) = a + (n-1)d

term5 = a+ 4d = 23
term12 = a + 11d = 72
subtract them
7d = 49
d = 7
sub into a+4d = 23
a + 28 = 23
a = -5

first three terms are -5 , 2, and 9

michelle · Answer

How do i get to the answers as shown above

Mpho · Answer

Thanks for helping me I wish we can work together