Question

so sánh

A=(3+1)(3^2+1)(3^4+1)(3^8+1)(3^16+1)

B=3^32+-1

 

 

Answer 1

A=(3+1)(3^2+1)(3^4+1)(3^8+1)(3^16+1)

=>2A=(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=\(\frac{3^{32}-1}{2}\)

 Đến đậy thì bạn có thể so sánh r, mik ko làm dc là vì B=3³²+-1 mik ko hỉu í bạn là dấu +hay -

Answer 2

A=(3+1)(3^2+1)(3^4+1)(3^8+1)(3^16+1) => 2A=(3-1)(3+1)(3^2+1)(3^4+1)(3^8+1)(3^16+1) => 2A=3^32 - 1 => A= (3^32 - 1) / 2

B = 3^32 - 1

=> A < B

Answer 3

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

=> A < B