Question

in an ap if first term = -2 and common difference =5 then find 'n', 'L'​

Answer 1

Answer:

Step-by-step explanation:

given a = -2 and d =5

An =  l-(n-1)d  and An= a +(n-1)d

from above we can write

      l-(n-1)d = a +(n-1)d

      l-a= (n-1)d + (n-1)d

      l-a=2(n-1)d

      l+2 = 2(n-1)5

      l+2 =10n -10

      l-10n = -12

         10n -  l = 12

      if n=1  l= -2

     if n=2  l= 8

     and so on