I can't solve this one:

Question

The second term of an arithmetic sequence is 24 and the fifth term is 3.Find the first term and the common difference.
How could I get the answers if there's only two given numbers?

Answer 1

2nd term = 24
5th term = 3

24-3 = 21
5-2 = 3

21/3 = 7
common difference = -7 since the terms are decreasing
so to find the first term, subtract -7 from 24

so the first term is equal to 31

Answer 2

traditional method:

a+d = 24
a+4d = 3

subtract them:
3d = -21
d = -7

sub into a+d = 24
a - 7 = 24
a = 31

first term is 31, commond difference is -7

Answer 3

how many terms are there in an arithmetic sequence those first term is -4 common difference 2 and last term is 24?

Answer 4

The second term if can arithmetic sequence is 24 and the fifth term is 3 find the first term and common difference