Question

find the 1st term of an ap having 9 terms whose last term is 28 and the sum of all terms is 144

Answer 1

use the formula
Sn=n/2(a+l)
where
Sn=144
l=28
n=9

Answer 2

formula is---S= n/2(a+l),a=1st term ,n= no. of terms,l=last term,s=sum

here,n=9,l=28,s=144...on solving,we get a=4...

hence,1st term=4