Question

Question 1 (iii)
Fill in the blanks in the following table, given that a is the first term, d the common difference and $a_n$ the $n^{th}$ term of the A.P.
$\begin{array}{ccccc}& a& d& n& a_n\\ \left(iii\right)& \dots \dots & -3& 18& -5\end{array}$

Answer 1

(iii) Given that,
$d=-3,n=18,a_n=-5$
We know that,
$a_n=a+(n-1)d-5=a+(18-1)(-3)-5=a+\left(17\right)(-3)-5=a-51a=51-5=46Hence,a=46$