一元二次方程练习题-含答案

1、经典解法20题 (1) (3x+1F2=7 (2) 9xA2-24x+16=11 (x+3)(x-6)=-8 2xA2+3x=0 6xA2+5x-50=0 ( 选学) xA2-4x+4=0(选学) (7) (x-2 ) A2=4(2x+3 ) (8) yA2+2 v2y-4=0 (9) ( x+1 ) A2-3(x+1)+2=0 (10) xA2+2ax-3aA2=0 （a为常数） (11) 2x9 + 7x = 4 . (12) x9 1 = 2 x (13) xA2 + 6x+5=0 (14) x A2 4x+ 3=0 (15) 7xA2 4x 3 =0 (16) x A2 6x+9 =0

2、 (17) x2+8x+16=9 (18) (x25)2=16 (19) x(x+2)=x(3-x)+1 (20) 6xA2+x-2=0 海量111题 1)xA2-9x+8=0 xA2+6x-27=0 xA2-2x-80=0 (4) xA2+10 x-200=0 (5) xA2-20 x+96=0 xA2+23x+76=0 (7) xA2-25x+154=0 (8) xA2-12x-108=0 (9) xA2+4x-252=0 (10) xA2-11x-102=0 (11) xA2+15x-54=0 (12) xA2+11x+18=0 (13) xA2-9x+20=0 (14) xA2+19x

3、+90=0 (15) xA2-25x+156=0 (16) xA2-22x+57=0 (17) xA2-5x-176=0 (18) xA2-26x+133=0 (19) xA2+10 x-11=0 (20) xA2-3x-304=0 (21) xA2+13x-140=0 (22) xT+13x-48=0 (23) xT+5x-176=0 (24) xA2+28x+171=0 (25) xA2+14x+45=0 (26) xA2-9x-136=0 (27) xA2-15x-76=0 (28) xA2+23x+126=0 (29) xA2+9x-70=0 (30) xA2-1x-56=0 (31)

4、 xA2+7x-60=0 (32) xA2+10 x-39=0 (33) xA2+19x+34=0 (34) xA2-6x-160=0 (35) xA2-6x-55=0 (36) xA2-7x-144=0 (37) xA2+20 x+5 仁0 (38) xA2-9x+14=0 (39) xA2-29x+208=0 (40) xA2+19x-20=0 (41) xA2-13x-48=0 (42) xA2+10 x+24=0 (43) xA2+28x+180=0 (44) xT-8x-209=0 (45) xT+23x+90=0 (46) xA2+7x+6=0 (47) xA2+16x+28=0

5、(48) xA2+5x-50=0 (49) xA2+13x-14=0 (50) xA2-23x+102=0 (51) xA2+5x-176=0 (52) xA2-8x-20=0 (53) xA2-16x+39=0 (54) xA2+32x+240=0 (55) xA2+34x+288=0 (56) xA2+22x+105=0 (57) xA2+19x-20=0 (58) xA2-7x+6=0 (59) xA2+4x-221=0 (60) xA2+6x-9 仁0 (61) xA2+8x+12=0 (62) xA2+7x-120=0 (63) xA2-18x+17=0 (64) xA2+7x-17

6、0=0 (65) xA2+6x+8=0 (66) xT+13x+12=0 (67) xH+24x+119=0 (68) xA2+11x-42=0 (69) xA20 x-289=0 (70) xA2+13x+30=0 (71) xA2-24x+140=0 (72) xA2+4x-60=0 (73) xA2+27x+170=0 (74) xA2+27x+152=0 (75) xA2-2x-99=0 (76) xA2+12x+1仁0 (77) xA2+17x+70=0 (78) xA2+20 x+19=0 (79) xA2-2x-168=0 (80) xA2-13x+30=0 (81) xA2-1

7、0 x-119=0 (82) xA2+16x-17=0 (83) xA2-1x-20=0 (84) xA2-2x-288=0 (85) xA2-20 x+64=0 (86) xA2+22x+105=0 (87) xA2+13x+12=0 (88) xT-4x-285=0 (89) xT+26x+133=0 (90) xA2-17x+16=0 (91) xA2+3x-4=0 (92) xA2-14x+48=0 (93) xA2-12x-133=0 (94) xA2+5x+4=0 (95) xA2+6x-9 仁0 (96) xA2+3x-4=0 (97) xA2-13x+12=0 (98) xA2

8、+7x-44=0 (99) xA2-6x-7=0 (100) xA2-9x-90=0 (101) xA2+17x+72=0 (102) xA2+13x-14=0 (103) xA2+9x-36=0 (104) xA2-9x-90=0 (105) xA2+14x+13=0 (106) xA2-16x+63=0 (107) xA2-15x+44=0 (108) xA2+2x-168=0 (109) xA2-6x-216=0 (110) xA2-6x-55=0 (111) xA2+18x+32=0 答案 (1) (3x+1F2=7 解：(3x+1F2=7/.(3x+1)A2=7/-3x+1= V7(

9、注意不要丢解)/-x= ( V7-1)/3 (2) 9xA2-24x+16=11 解：9xA2-24x+16=11(3x-4)A2=11/-3x-4= V(1/-x= ( V 11+4)/3原方程的解为 x1=( V11+4)/3x2=(- Vl1+4)/3 (3) (x+3)(x-6)=-8 解：(x+3)(x-6)=-8 化简整理得 xA2-3x-10=0 ( 方程左边为二次三项式，右 边为零)(x-5)(x+2)=0 (方程左边分解因式)*5=0或x+2=0 (转化成两 个一元一次方程)：x1=5,x2=-2是原方程的解。 2xA2+3x=0 解：2xA2+3x=0 x(2x+3)=0

10、(用提公因式法将方程左边分解因式)以=0 或2x+3=0 (转化成两个一元一次方程)仁0 , x2=-3/2是原方程的解。 注意：有些同学做这种题目时容易丢掉x=0这个解，应记住一元二次方程有两 个解。 6xA2+5x-50=0 （ 选学） 解：6x2+5x-50=0(2x-5)(3x+10)=0 (十字相乘分解因式时要特别注意符 号不要出错).厶巧二。或3x+10=0眾仁5/2, x2=-10/3是原方程的 解。 （6）xA2-4x+4=0 （选学） 2)(x-2 )=0.-x1=2 ,x2=2 是原方程的解。 (7) (x-2 ) A2=4(2x+3 ) A2 解.(x-2)A2-4(2x

11、+3)A2=0.x-2+2(2x+3)(x-2-2(2x+3)=0. (5x+4)(-5x-8)=0. x1=-4/5, x2=-8/5 (8) yA2+2 v2y-4=0 解(y+ v2)A2-2-4=0. (y+ v2F2=6. y+ v2= v6. y=- v2 a6. 解(x+1-1)(x+1-2)=0. x(x-1)=0. x仁0, x2=1. (10) xA2+2ax-3aA2=0(a 为常数) 解(x+3a)(x-a)=0. x仁-3a, x2=a. 解：方程可变形为2xA2 + 7x 4 = 0 . a = 2 , b = 7, c= 4, b2 4ac = 72 4 X2 x

12、(4) = 81 0, x = . -x1 = , x2 = 4 . (12用2 1 = 2 x 解：方程可变形为xA2 2 x 1 = 0. a = 1 , b = 2 , c= 1, b2 4ac = ( 2 )2 4X1 X( 1) = 16 0 . x = . x1 = + 2, x2 = 2 (13) xA2 + 6x+5=0 解：原方程可化为(x+5)(x+1)=0 x1=-5x2=-1 (14) x A2 4x+ 3=0 解：原方程可化为(x-3)(x-1)=0 x1=3x2=1 (15) 7xA2 4x 3 =0 解原方程可化为(7x+3)(x-1)=0 x1=-3/7x2=1

13、 (16) x A2 6x+9 =0 解原方程可化为 (x-3)A2=0 x1=x2=3 (17) x2+8x+16=9 (18) (x25)2=16 解：x2-5=4 或 x2-5=-4 x2=9 或 x2=1 x1=3,x2=-3,x3=1,x4=-1 (19) x(x+2)=x(3-x)+1 解 x2+2x=3x-x 2+1 2x2-x -1=0 解原方程可化为(3x+2)(2x-1)=0 (x+2/3)(x-1/2)=0 x1=-2/3x2=1/2 这是20道有过程的，还有一些没有过程，只有答案的 1)xA2-9x+8=0答案：x1=8 x2=1 xA2+6x-27=0答案：x仁3 x

14、2=-9 (4)xA2+10 x-200=0 答案：x仁-20 x2=10 (5)xA2-20 x+96=0 答案：x1=12 x2=8 xA2+23x+76=0 答案：x1=-19 x2=-4 (7)xA2-25x+154=0 答案：x1=14 x2=11 (8)xA2-12x-108=0 答案：x仁-6 x2=18 (9)xA2+4x-252=0 答案：x1=14 x2=-18 (10)xA2-11x-102=0 答案：x仁17 x2=-6 (11)xA2+15x-54=0 答案：x1=-18 x2=3 (12)xA2+11x+18=0 答案：x仁-2 x2=-9 (13)xA2-9x+2

15、0=0 答案：x1=4 x2=5 (14)xA2+19x+90=0 答案：x1=-10 x2=-9 (15)xA2-25x+156=0 答案：x1=13 x2=12 (16)xA2-22x+57=0 答案：x1=3 x2=19 (17)xA2-5x-176=0 答案：x1=16 x2=-11 (18)xA2-26x+133=0 答案：x1=7 x2=19 (19)xA2+10 x-11=0 答案：x1=-11 x2=1 (20)xA2-3x-304=0 答案：x仁-16 x2=19 (21)xA2+13x-140=0 答案：x1=7 x2=-20 (22)xA2+13x-48=0 答案：x1=

16、3 x2=-16 (23)xA2+5x-176=0 答案：x1=-16 x2=11 (24)xA2+28x+171=0 答案：x仁-9 x2=-19 (25)x2+14x+45=0 答案：x仁-9 x2=-5 (26)xA2-9x-136=0 答案：x仁-8 x2=17 (27)xA2-15x-76=0 答案：x1=19 x2=-4 (28)xA2+23x+126=0 答案：x仁-9 x2=-14 (29)xA2+9x-70=0 答案：x仁-14 x2=5 (30)xA2-1x-56=0 答案：x1=8 x2=-7 (31)xA2+7x-60=0 答案：x1=5 x2=-12 (32)xA2+

17、10 x-39=0 答案：x1=-13 x2=3 (33)xA2+19x+34=0 答案：x1=-17 x2=-2 (34)xA2-6x-160=0 答案：x1=16 x2=-10 (35)xA2-6x-55=0 答案：x仁11 x2=-5 (36)xA2-7x-144=0 答案：x仁-9 x2=16 (37)xA2+20 x+5 仁0 答案：x仁-3 x2=-17 (38)xA2-9x+14=0 答案：x1=2 x2=7 (39)xA2-29x+208=0 答案：x1=16 x2=13 (40)xA2+19x-20=0 答案：x1=-20 x2=1 (41)xA2-13x-48=0 答案：x

18、1=16 x2=-3 (42)xA2+10 x+24=0 答案：x仁-6 x2=-4 (43)xA2+28x+180=0 答案：x1=-10 x2=-18 (44)xA2-8x-209=0 答案：x1=-11 x2=19 (45)xA2+23x+90=0 答案：x1=-18 x2=-5 (46)xA2+7x+6=0 答案：x仁-6 x2=-1 (48)xT+5x-50=0 答案：x仁-10 x2=5 (49)xT+13x-14=0 答案：x1=1 x2=-14 (50)xA2-23x+102=0 答案：x1=17 x2=6 (51)xA2+5x-176=0 答案：x1=-16 x2=11 (5

19、2)xA2-8x-20=0 答案：x仁-2 x2=10 (53)xA2-16x+39=0 答案：x1=3 x2=13 (54)xA2+32x+240=0 答案：x1=-20 x2=-12 (55)xA2+34x+288=0 答案：x1=-18 x2=-16 (56)xA2+22x+105=0 答案：x仁-7 x2=-15 (57)xA2+19x-20=0 答案：x1=-20 x2=1 (58)xA2-7x+6=0 答案：x1=6 x2=1 (59)xA2+4x-221=0 答案：x1=13 x2=-17 (60)xA2+6x-9 仁0 答案：x仁-13 x2=7 (61)xA2+8x+12=0

20、 答案：x仁-2 x2=-6 (62)xA2+7x-120=0 答案：x1=-15 x2=8 (63)xA2-18x+17=0 答案：x1=17 x2=1 (64)xA2+7x-170=0 答案：x1=-17 x2=10 (65)xA2+6x+8=0 答案：x仁-4 x2=-2 (66)xA2+13x+12=0 答案：x仁-1 x2=-12 (67)xA2+24x+119=0 答案：x仁-7 x2=-17 (68)xA2+11x-42=0 答案：x1=3 x2=-14 (69)xA20 x-289=0 答案：x1= 17 x2=-17 (70)xA2+13x+30=0 答案：x仁-3 x2=-

21、10 (71)xA2-24x+140=0 答案：x1=14 x2=10 (72)xA2+4x-60=0 答案：x仁-10 x2=6 (73)xA2+27x+170=0 答案：x1=-10 x2=-17 (74)xA2+27x+152=0 答案：x1=-19 x2=-8 (75)xA2-2x-99=0 答案：x仁11 x2=-9 (76)xA2+12x+11=0 答案：x1=-11 x2=-1 (77)xA2+17x+70=0 答案：x1=-10 x2=-7 (78)xA2+20 x+19=0 答案：x1=-19 x2=-1 (79)xA2-2x-168=0 答案：x1=-12 x2=14 (80)xA2-13x+30=0 答案：x1=3 x2=10 (81)xA2-10 x-119=0 答案：x仁17 x2=-7 (82)xA2+16x-17=0 答案：x1=1 x2=-17 (83)xA2-1x-20=0 答案：x1=5 x2=-4 (84)xA2-2x-288=0 答案：x1=18 x2=-16 (85)xA2-20 x+64=0 答案：x1=16 x2=4 (86)xA2+22x+105=0 答案：x仁-7 x2=-15 (87)xA2+13x+12=0 答案：x仁-1 x2=