Question

Tính nhanh bằng cách dùng hằng đẳng thức:

B=(2+1)(2²+1)(2⁴+1)(2⁸+1)(2¹⁶+1)−2³².

Answer 1

B=(2+1)(2²+1)(2⁴+1)(2⁸+1)(2¹⁶+1)−2³²

=1.(2+1)(2²+1)(2⁴+1)(2⁸+1)(2¹⁶+1)−2³²

=(2-1)(2+1)(2²+1)(2⁴+1)(2⁸+1)(2¹⁶+1)−2³²

=(2²-1)(2²+1)(2⁴+1)(2⁸+1)(2¹⁶+1)−2³²

=(2⁴-1)(2⁴+1)(2⁸+1)(2¹⁶+1)−2³²

=(2⁸-1)(2⁸+1)(2¹⁶+1)−2³²

=(2¹⁶-1)(2¹⁶+1)−2³²

=2³²-1-2³²

=-1

Answer 2

A = ( 2 +1 )( 2^2  + 1 )...(2^16+1) - 2^32

A = ( 2 - 1) ( 2 + 1 )(2^2 + 1) .... (2^16 + 1) - 2^32

A = (2^2 - 1) (2^2 + 1) ...(2^16 + 1) - 2^32

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

A = ( 2^8 - 1)( 2^ 8 + 1) ( 2^ 16 + 1)- 2^32

A = ( 2^16 -  1 )( 2^16 + 1) - 2^32

A = 2^32 - 1 - 2^32

A = - 1

Answer 3

x=-1