第二十一章一元二次方程解方程50题专项训练 2023—2024学年人教版数学九年级上册

第二十一章一元二次方程解方程50题专项训练 (1)(x-5)=8x-5) (7)4x-1-1=8: (2)2x2-4x-3=0. (8)2x2-3x+1=0. (3)x2-3x-4=0: (9)2x2-7x=0 (4)xx-2)=1; (10)(x+4)=5x+4) (5)x2-2x+1=9: (11)(x-12-25=0 (6)2x2-2x-1=0. (12)(5x-1=35x-1 (13)x2-4x-3=0 (19)(4x2-9-9(2.x+3)=0 (14)2x2+6x+2=0 (20)(2x-3)-4=0 (15)x2-2x=0: (21)x2-8x-9984=0 (16)x2-7x+2=0. (22)x2+8x=9(用配方法解) (17)(4x-1)°-10(4x-1-24=0 (23)3x2-5x=2(用公式法解) (18)2x2-2x-5=0 (24)(x-4)2=9 2 (25)x2-7x+6=0 (31)x2-3x=0: (26)(x+3)2=2x+6 (32)(3x-4)2=(4x-3)2: (27)(x+3)2=(1-2x (33)2x2-5x+3=0. (28)用公式法：2x2-4x-1=2. (34)x(x-2)+x-2=0: (29)用配方法：4x2-3=4x, (35)2x2-x-1=0. (30)用分解因式法：x-1=(1-x, (36)(x-3-4=0: (37)(x+22-2(x+21=3. (43)x2-1=4x. (38)x2-6x=3 (44)x2+3x+1=0: (39)(x-7)2=2(x-7). (45)(x-1)2-2(x-1)=0. (40)x2-2x-5=0: (46)x2-5x-6=0: (41)3x-22-12=0. (47)4(x-3)+xx-3=0, (42)xx-4+x-4=0: (48)(x+1=7x+7. (49)4x2-8x-3=0 (50)(5-2x=9(x+2);(因式分解法) 参考答案 (1)x=5,2=13: (2)斯=2+i而 2 2 (3)x=-1,x2=4 (4)x=1+V2,x,=1-2 (5)x1=-2,x2=4 (6)=+5.k=1-5 2 5 1 (7)=24=2 1 (8)x=1,为-2 (9)x=0,为=2 (10)x1=-4,x2=1 (11)x=6,x2=-4: 1 4 (12)=56=3 (13)x=2+V万，x,=2-V万： 04s=5-3. 2 ，6=5-3 2 (15)x=0,x3=2 (16)5=7+④， 2 57团 2 w=-6号 13 1+行。1-行 (18)x,= 23 2 3 (19)x=6,x2= 2 5 1 (20)=25-2 (21)x1=104,x2=-96 (22)x=1,x2=-9: 1 (23)x=2,x2= 3 (24)x=7,为2=1： (25)x=1,x2=6: (26)x1=-1,x2=-3; 27)=,5=4 (28)x=2+10 2 1 3 (29)1=-262 (30)x1=1,=2 (31)x=0,x2=3 (32)x1=1,x2=-1 3 (3)X=26=1 (34)=-1,6=2 35)=分61 (36)x=5,x2=1 (37)x1=1,x2=-3 (38)x=3+2V5,,=3-25 (39)x=7,x2=9 (40)x=1+V6,5,=1-6 (41)x1=4,x2=0 (42)x1=4,x2=-1 (43)x=2+5,x,=2-5 (44):=-3+5 2 2 (45)x=1,x2=3. (46)x=-1,x2=6 (47)x1=3,x2=4 (48)x1=-1,x2=6 (49)x=2+V5 2 （0》5-1l-