因式分解之十字相乘法专项练习题
因式分解之十字相乘法专项练习题
2
(1) a2-7a+6; (2) x +12x +11
4222
(3) x -x -20; (4) x -3xy +2y ;
(5) y 2-13yb +36b 2
;
(7) x 2-4x +3;
(9) x 4+7x 2-18;
(11)x 2y 2-5x 2y -6x 2
;
(13)(a +b ) 2-4(a +b ) x +3
(15)5x2-8x -13;
(17)15x2+x-2;
(6) -a 3-4a 2+12a ;
(8) x 4+6x 2
+8;
(10) x 2
+18x +17;
(12)4n2+4n-15;
(14)6a2+a-35; (16)4x2+15x+9; (18)6y2+19y+10;
22
(19) m n +3mn -10; (20)7(x-1) 2+4(x-1) -20;
222
(21) y -13yb +36b (22)-a -10a +9
(23)-a 3-4a 2
+12a
(25)(x 2-3) 2-4x 2
(27) 2x 2+5x -7
(29) 3b 2+14b -5
(31)3a 2-8a +4
(24) (x +2y ) 2+3(x +2y ) -10 (26) 2x 2-x -3 (28) 3a 2-2a -1 (30)2x 2+15x +7 (32)5x 2+7x -6
参考答案: (1)(a-6)(a-1), (3) (3x-1) (6x-5) , (5) (x+1)(2x+1), (7) (2x-3) (3x-2) , (9) (2x-3) (3x-1) , (11) (x-2) (10x-1) , (13) (2n+5)(2n-3) , (15) (x+1)(5x-13) , (17) (3x-1) (5x=2), (19) (3a-b) (5b-a) , (2)(2x+5)(4x-7) (4)-(4y-5) (5y+4) (6) (y+2)(2y-3) (8) (a-3) (3a+2) (10) (2m+1)(2m+3) (12) (2m-3) (4m-5) (14) (2a+5)(3a-7) (16) (x+3)(4x+3) (18) (2y+5)(3y+2) (20) (x+1)(7x-17)