Question

Which of the numbers below could be terms in the sequence an=4n-7 A)29 B)21 C)20 D)28

Answer 1

A)29 and B) 21,

Explanation:

First,in the sequence
`a_n=4n-7` , the parameter
`n` must to be a integer.

Second, we need to solve the equations by
`n`.

`n=(a_n+7)/4`

All the option in the problem represent an
`a_n`

Then, we need to prove all number in the options, if the result is a integer number, this option can be part of the sequence.

For A)

`n=(29+7)/4=9\\`

For B)

`n=(21+7)/4=7\\`

For C)

`n=(20+7)/4=6.75\\`

For D)

`n=(28+7)/4=8.75\\`

Only A) and B) only A and B meet the requirement