【正文】
x5= x10 C . ( x + 1)( x - 1) = x2- 1 D . (2 x )5= 2 x5 C 2 . 計(jì)算100022522- 2482 的結(jié)果是 ( ) A . 12 B . 10 00 C . 500 D . 20 00 C 3 . (2 017 寧夏 ) 如圖,從邊長(zhǎng)為 a 的大正方形中剪掉一個(gè)邊長(zhǎng)為 b 的小正方形,將陰影部分沿虛線剪開,拼成右邊的矩形.根據(jù)圖形的變化過程寫出的一個(gè)正確的等式是 ( ) D A . ( a - b )2= a2- 2 a b + b2 B . a ( a - b ) = a2- a b C . ( a - b )2= a2- b2 D . a2- b2= ( a + b )( a - b ) 4 . 化簡(jiǎn) (3 + 1) (32+ 1) (34+ 1) (38+ 1) 得 ( ) A . (38+ 1)2 B . (38- 1)2 C . 316- 1 D . 12 (316- 1) D 【解析】原式=12 (3 - 1)(3 + 1) (32+ 1) ( 34+ 1) (38+ 1) =12(32- 1)(32+ 1) (34+ 1)(38+ 1) =12(34- 1)(34+ 1) (38+ 1) =12(38- 1)(38+