The (n-1)th term of an A.P. is given by 7,12,17, 22,... is

 The (n-1)th term of an A.P. is given by 7,12,17, 22,... is

Solution:- Given the ap is 7,12,17,22.......

a=7 , d=12-7=5

(n-1)th term of ap is 

an-1=a+(n-1-1)d

an-1=7+(n-2)×5

an-1=7+5n-10

an-1=5n-3 ans....