Question -
Answer -
(i) Let A be theArithmetic mean
Then 7, A, 13 are inAP
Now, let us solve
A-7 = 13-A
2A = 13 + 7
A = 10
(ii) Let A be theArithmetic mean
Then 12, A, – 8 are inAP
Now, let us solve
A – 12 = – 8 – A
2A = 12 + 8
A = 2
(iii) Let A be theArithmetic mean
Then x – y, A, x + yare in AP
Now, let us solve
A – (x – y) = (x + y)– A
2A = x + y + x – y
A = x