Question

Find the 80th term following arithmetic sequence 8,14,20,26

Answer 1

Answer: 482

Explanation:

`\displaystyle\ \Large \boldsymbol{Rule:} \\\\\boxed{ \huge \boxed{a_n=a_1+(n-1)d }} } \ \ \\\\\\ 8 \underbrace{}_6 14 \underbrace{}_620\underbrace{}_626 ......a_(80)=? \\\\\\a_1=8 \ \ ; \ \ d=6 \\\\\\ a_(80)=8+(80-1)\cdot 6=480+8-6=482 \\\\\\\\ Answer: \boxed{\boldsymbol{ a_(80)=482}}`

Answer 2

The 80th term is 482

Explanation:

8,14,20,26

This is an arithmetic sequence

Find the common difference by taking the second term and subtracting the first term

14-8 = 6

We are adding 6 each time

The formula for an arithmetic sequence is

an =a1+d(n-1) where a1 is the first term, d is the common difference and n is the term we are looking for

a80 = 8+6(80-1)

= 8 + 6*79

= 8+474

= 482

The 80th term is 482