Question

In an arithmetic sequence if a1 =7 and d = 3, find a64

Answer 1

Answer:

$a_{64}=196$

Step-by-step explanation:

Arithmetic sequence

General form of an arithmetic sequence: $a_n=a+(n-1)d$

where:

• $a_n$ is the nth term
• a is the first term
• d is the common difference between terms

Given:

• $a_1=7$

• $d=3$

Substituting these into the equation to find the nth term:

$\implies a_n=7+(n-1)3$

$\implies a_n=3n+4$

To find the 64th term, substitute n = 64 into the formula:

$\implies a_{64}=3(64)+4=196$

Answer 2

Answer:

196

Step-by-step explanation:

Formula for the nth term

• aₙ = a₁ + (n - 1) d

Taking n = 64

• a₆₄ = 7 + 63(3)
• a₆₄ = 7 + 189
• a₆₄ = 196