Which of the following properly uses a polynomial identity to detect if 22k−1 is prime?(1 point)
Responses
22k−1=(2k+1)(2k−1), so 22k−1 is prime.
2 superscript 2 k baseline minus 1 equals left parenthesis 2 superscript k baseline plus 1 right parenthesis left parenthesis 2 superscript k baseline minus 1 right parenthesis , so 2 superscript 2 k baseline minus 1 is prime.
22k−1=(2k+1)(2k−1), so 22k−1 is not prime.
2 superscript 2 k baseline minus 1 equals left parenthesis 2 superscript k baseline plus 1 right parenthesis left parenthesis 2 superscript k baseline minus 1 right parenthesis , so 2 superscript 2 k baseline minus 1 is not prime.
22k−1=(22+1)(2k−1), so 22k−1 is prime.
2 superscript 2 k baseline minus 1 equals left parenthesis 2 superscript 2 baseline plus 1 right parenthesis left parenthesis 2 superscript k baseline minus 1 right parenthesis , so 2 superscript 2 k baseline minus 1 is prime.
22k−1=(22+1)(2k−1), so 22k−1 is not prime.