Question

Determine the ap whose fifth term is 15 and the sum of its 3rd and 8th term is 34

Answer 1

Here is the answer, hope it helps.

Answer 2

Step-by-step explanation:

t5 = 15

a+ 4d = 15........(1)

t3 + t8 = 34

a+ 2d + a + 7d = 34

2a + 9d = 34.......(2)

multiply (1) by 2 ---> 2a + 8d = 30.....(3)

Now let's solve (3) &(2)

2a + 9d = 34

2a + 8d = 30

_____________

d = 4

substitute d = 4 in (3)

2a + 32 = 30

a = -1

t1 = -1

t2 = 3

t3 = 7

So, your A.P is -1,3,7