Question

If the common difference of an A.P is 3 then find a15-a8

Answer 1

Step-by-step explanation:

a15=a+14d

a8= a+7d

a15-a8= a+14d-a-7d

a15-a8= 7d

a15-a8= 21

Answer 2

       = a + 14 * 3

Answer:

21

Step-by-step explanation:

d = 3

an = a + (n-1) d

a15 = a + (15-1)3

a15 = a+ 14*3

a15 = a + 42 ---------i

a8 = a + (8-1) 3

  =   a + 7 * 3

a8 = a + 21 ----ii

Subtract ii from i

a + 42 - ( a  +21 )

a + 42 - a - 21

21

Hope it will help you...........

Mark it as brain-list.