Question

If 18,a,b,-3 are in A. P., then a and b are??

Answer 1

A.P:- 18,a,b,-3 . find a nd b ?
answer;- a=18 nd d=? so 1st we find difference .
ist term =a
a=a , 2nd = a+ d
18=a
-3=a+3d {sign chnge}
21=-3d ---> 21/-3= d ...... d=-7
then A.P series = 18,11,4,-3
{2nd term = a+d
18+(-7)=11 }