=( )- 1 - 1 ( - 1) 1+1 2- 1 = 1+ - 1S U T M

2

- 1

- 1

+ 1

:

=

( )

_{- 1}

_{- 1}

₍

_{- 1)}

2

_{- 1}

+1

2

- 1

= 1+

- 1

S u t m: OÀN TI N TRUNG - THCS Hoàng V n Th - N