Question

The 5th term of an arithmetic sequence is 38 and the 9th term is 66 what is its 25th term?

Answer 1

Answer:

25th term=178

Step-by-step explanation:

we know, tn=a+(n-1)d

5th term of AP = >a+4d=38  ---------------------(1)

9th term of AP =>a+8d=66    ----------------------(2)

subtracting (1) from (2)

a+8d-a-4d=66-38

4d=28

d=7

substituting value of d in (1)

a+ (4*7)=38

a+28=38

a=38-28

a=10

Therefore, 25th term= a+24d= 10 + 24*7

                                                 =178