The 5th and 10th terms of A. P are - 12 and 27 respectively. Find the A. P and its 15th term. (B) The first three terms of an A. P are x and the 10th term.

Answer 1

Using the basic definitions:

a + 4d = -12
a + 9d = 27
subtract them
5d = 39
d = 39/5 or 7.8
sub back in ....
a+4(7.8) = -12
a = -43.2

sequence is:
-43.2 , -35.4, -27.6, -19.8, -12, ...

term15 = a + 14 d
= .....

B) The first three terms of an A. P are x and the 10th term.
That statement makes no sense to me.

Answer 2

This is absolutely correct, like really correct 💟💘💝💝