234k views
3 votes
The 10th term of an A.P is double the 2nd term Find the 8th term, given that the first term is 7

1 Answer

4 votes

Step 1

The nth term of an A.P is given as;


\begin{gathered} a_n=a_1+(n-1)d \\ a_1=7 \end{gathered}

Step 2


\begin{gathered} a_2=7+(2-1)d \\ a_2=7+d \\ a_(10)=2(7+d)=14+2d \\ a_(10)=7+9d \\ 7+9d=14+2d \\ 7d=7 \\ d=1 \end{gathered}

Hence the 8th term will be;


\begin{gathered} a_8=7+(8-1)d \\ a_8=7+7(1) \\ a_8=14 \end{gathered}

User David Derman
by
5.8k points