Question

Number 12: Write an equation to find the nth term then find a24

Answer 1

-1, -4, -7, -10....

The nth term of an arithmetic sequence is given by the formula:

`a_n=a_1+(n-1)\cdot r`

We can check that the first term, a1, is -1 and the rate of change, r is -3, therefore, we have:

`\begin{gathered} a_n=-1+(n-1)\cdot(-3) \\ a_n=-3n+2 \\ a_(24)=-3\cdot24+2=-70 \end{gathered}`