Question

Write the first five terms of the sequence whose general term, a_n, is given as a_n= -3n+9

Answer 1

To find the terms, substitute n by the number of the term, according to the steps.

Step 01: Find a₁.

To do it, substitute n by 1.

`\begin{gathered} a_n=-3n+9 \\ a_1=-3\cdot1+9 \\ a_1=-3+9 \\ a_1=6 \end{gathered}`

Step 02: Find a₂.

`\begin{gathered} a_2=-3\cdot2+9 \\ a_2=-6+9 \\ a_2=3 \end{gathered}`

Step 03: Find a₃.

`\begin{gathered} a_3=-3\cdot3+9 \\ a_3=-9+9 \\ a_3=0 \end{gathered}`

Step 04: Find a₄.

`\begin{gathered} a_4=-3\cdot4+9 \\ a_4=-12+9 \\ a_4=-3 \end{gathered}`

Step 05: FInd a₅.

`\begin{gathered} a_5=-3\cdot5+9 \\ a_5=-15+9 \\ a_5=-6 \end{gathered}`

In summary:

a₁ = 6

a₂ = 3

a₃ = 0

a₄ = -3

a₅ = -6