find the 98th term of the arithmetic sequence -10, -8, -6,...
find the 98th term of the arithmetic sequence -10, -8, -6,...
Answer
Explanation:
Step1: Find the common difference
The common difference (d) of an arithmetic sequence is (d=a_{n + 1}-a_{n}). Given (a_{1}=-10), (a_{2}=-8), then (d=-8-\left(-10\right)=2)
Step2: Use the formula for the (n)th term of an arithmetic sequence
The formula for the (n)th term of an arithmetic sequence is (a_{n}=a_{1}+(n - 1)d). Here (a_{1}=-10), (d = 2), (n = 98) Substitute these values into the formula: [ \begin{align*} a_{98}&=-10+(98 - 1)\times2\ &=-10+97\times2\ &=-10 + 194 \end{align*} ]
Answer:
(184)