Question

[Hà Ngân Trần]

so sánh A và B:

A= 3³²-1

B= (3+1)(3²+1)(3⁴+1)(3⁸+1)(3¹⁶+1)

Answer 1

[Trần Tiến Pro ✓]

B = ( 3 + 1 ).( 3² + 1 ).(3⁴+1).(3⁸+1).(3¹⁶+1)

=> 2B = 2.(3+1).(3²+1).(3⁴+1).(3⁸+1).(3¹⁶+1)

=> ( 3 -1 ).(3+1).(3²+1).(3⁴+1).(3⁸+1).(3¹⁶+1)

=> ( 3²-1).(3²+1).(3⁴+1).(3⁸+1).(3¹⁶+1)

=> ( 3⁴-1).(3⁴+1).(3⁸+1).(3¹⁶+1)

=> ( 3⁸-1).(3⁸+1).(3¹⁶+1)

=> ( 3¹⁶-1).( 3¹⁶ + 1)

= 3³²-1

=> A = 3³²-1:2<3³²-1