Question

If common difference of an ap is 5 then find a 18 - 813

Answer 1

if we have to find a18 - 813 then answer is a - 728.

d=5  

a₁₈= a + 17d

    = a + 17(5)

    = a + 85

a₁₈ - 813 = a + 85 - 813 = a - 728