资源描述
精品文档，仅供学习与交流，如有侵权请联系网站删除经典解法20题（1）(3x+1)2=7（2）9x2-24x+16=11 (3) (x+3)(x-6)=-8 (4) 2x2+3x=0 (5) 6x2+5x-50=0 (选学） (6)x2-4x+4=0 （选学）(7)（x-2）2=4（2x+3）2（8）y2+22y-4=0（9）（x+1）2-3（x+1)+2=0（10）x2+2ax-3a2=0（a为常数） (11)2x27x4(12)x212 x（13） x2 + 6x+5=0(14) x 24x+ 3=0 (15)7x2 4x3 =0 (16)x 26x+9 =0 (17)x+8x+16=9(18)(x-5)=16(19)x(x+2)=x(3-x)+1(20) 6x2+x-2=0海量111题1)x2-9x+8=0 (2)x2+6x-27=0 (3)x2-2x-80=0(4)x2+10x-200=0(5)x2-20x+96=0 (6)x2+23x+76=0 (7)x2-25x+154=0 (8)x2-12x-108=0 (9)x2+4x-252=0 (10)x2-11x-102=0 (11)x2+15x-54=0 (12)x2+11x+18=0 (13)x2-9x+20=0 (14)x2+19x+90=0 (15)x2-25x+156=0 (16)x2-22x+57=0 (17)x2-5x-176=0(18)x2-26x+133=0 (19)x2+10x-11=0 (20)x2-3x-304=0 (21)x2+13x-140=0 (22)x2+13x-48=0 (23)x2+5x-176=0 (24)x2+28x+171=0 (25)x2+14x+45=0 (26)x2-9x-136=0 (27)x2-15x-76=0 (28)x2+23x+126=0 (29)x2+9x-70=0 (30)x2-1x-56=0 (31)x2+7x-60=0 (32)x2+10x-39=0 (33)x2+19x+34=0 (34)x2-6x-160=0 (35)x2-6x-55=0 (36)x2-7x-144=0 (37)x2+20x+51=0 (38)x2-9x+14=0 (39)x2-29x+208=0(40)x2+19x-20=0 (41)x2-13x-48=0(42)x2+10x+24=0(43)x2+28x+180=0 (44)x2-8x-209=0(45)x2+23x+90=0 (46)x2+7x+6=0 (47)x2+16x+28=0 (48)x2+5x-50=0 (49)x2+13x-14=0 (50)x2-23x+102=0 (51)x2+5x-176=0 (52)x2-8x-20=0 (53)x2-16x+39=0 (54)x2+32x+240=0 (55)x2+34x+288=0 (56)x2+22x+105=0 (57)x2+19x-20=0 (58)x2-7x+6=0 (59)x2+4x-221=0 (60)x2+6x-91=0 (61)x2+8x+12=0 (62)x2+7x-120=0 (63)x2-18x+17=0 (64)x2+7x-170=0 (65)x2+6x+8=0 (66)x2+13x+12=0 (67)x2+24x+119=0 (68)x2+11x-42=0 (69)x20x-289=0 (70)x2+13x+30=0 (71)x2-24x+140=0 (72)x2+4x-60=0 (73)x2+27x+170=0 (74)x2+27x+152=0 (75)x2-2x-99=0 (76)x2+12x+11=0 (77)x2+17x+70=0 (78)x2+20x+19=0 (79)x2-2x-168=0(80)x2-13x+30=0 (81)x2-10x-119=0 (82)x2+16x-17=0 (83)x2-1x-20=0(84)x2-2x-288=0 (85)x2-20x+64=0 (86)x2+22x+105=0 (87)x2+13x+12=0 (88)x2-4x-285=0 (89)x2+26x+133=0 (90)x2-17x+16=0 (91)x2+3x-4=0 (92)x2-14x+48=0 (93)x2-12x-133=0 (94)x2+5x+4=0 (95)x2+6x-91=0 (96)x2+3x-4=0 (97)x2-13x+12=0 (98)x2+7x-44=0 (99)x2-6x-7=0 (100)x2-9x-90=0 (101)x2+17x+72=0 (102)x2+13x-14=0 (103)x2+9x-36=0 (104)x2-9x-90=0 (105)x2+14x+13=0 (106)x2-16x+63=0 (107)x2-15x+44=0 (108)x2+2x-168=0 (109)x2-6x-216=0 (110)x2-6x-55=0 (111)x2+18x+32=0 答案（1）(3x+1)2=7解：(3x+1)2=7 (3x+1)2=7 3x+1=7(注意不要丢解) x= (7-1)/3（2）9x2-24x+16=11 解： 9x2-24x+16=11 (3x-4)2=11 3x-4=11 x= (11+4)/3 原方程的解为x1=(11+4)/3 x2=(-11+4)/3 (3) (x+3)(x-6)=-8 解：(x+3)(x-6)=-8 化简整理得 x2-3x-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) x-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。 (4) 2x2+3x=0 解：2x2+3x=0 x(2x+3)=0 (用提公因式法将方程左边分解因式) x=0或2x+3=0 (转化成两个一元一次方程) x1=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。 (5) 6x2+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) 2x-5=0或3x+10=0 x1=5/2, x2=-10/3 是原方程的解。 (6)x2-4x+4=0 （选学）解：x2-4x+4 =0 （4 可分解为2 2 ，此题可用因式分解法） (x-2)(x-2 )=0 x1=2 ,x2=2是原方程的解。(7)（x-2）2=4（2x+3）2解.(x-2)2-4(2x+3)2=0. x-2+2(2x+3)(x-2-2(2x+3)=0. (5x+4)(-5x-8)=0. x1=-4/5, x2=-8/5（8）y2+22y-4=0解(y+2)2-2-4=0. (y+ 2)2=6. y+2=6. y=-26. y1=-2+6； y2=-2-6.（9）（x+1）2-3（x+1)+2=0解(x+1-1)(x+1-2)=0. x(x-1)=0. x1=0, x2=1.（10）x2+2ax-3a2=0（a为常数）解 (x+3a)(x-a)=0. x1=-3a, x2=a.(11)2x27x4解：方程可变形为2x27x40a2，b7，c4，b24ac7242(4)810，x x1 ，x24(12)x212 x 解：方程可变形为x22 x10a1，b2 ，c1，b24ac(2 )241(1)160x x1 2，x2 2（13） x2 + 6x+5=0解：原方程可化为(x+5)(x+1)=0 x1=-5 x2=-1(14) x 24x+ 3=0 解：原方程可化为(x-3)(x-1)=0x1=3 x2=1(15)7x2 4x3 =0 解原方程可化为 (7x+3)(x-1)=0x1=-3/7 x2=1(16)x 26x+9 =0 解原方程可化为(x-3)2=0x1=x2=3(17)x+8x+16=9解：(x+4)=9x+4=3或x+4=-3x1=-1,x2=-7(18)(x-5)=16解：x-5=4或x-5=-4x=9或x=1x1=3,x2=-3,x3=1,x4=-1(19)x(x+2)=x(3-x)+1解x+2x=3x-x+12x-x-1=0(2x+1)(x-1)=0x1=-1/2 x=1(20) 6x2+x-2=0解原方程可化为(3x+2)(2x-1)=0(x+2/3)(x-1/2)=0x1=-2/3 x2=1/2这是20道有过程的，还有一些没有过程，只有答案的。1)x2-9x+8=0 答案：x1=8 x2=1 (2)x2+6x-27=0 答案：x1=3 x2=-9 (3)x2-2x-80=0 答案：x1=-8 x2=10 (4)x2+10x-200=0 答案：x1=-20 x2=10 (5)x2-20x+96=0 答案：x1=12 x2=8 (6)x2+23x+76=0 答案：x1=-19 x2=-4 (7)x2-25x+154=0 答案：x1=14 x2=11 (8)x2-12x-108=0 答案：x1=-6 x2=18 (9)x2+4x-252=0 答案：x1=14 x2=-18 (10)x2-11x-102=0 答案：x1=17 x2=-6 (11)x2+15x-54=0 答案：x1=-18 x2=3 (12)x2+11x+18=0 答案：x1=-2 x2=-9 (13)x2-9x+20=0 答案：x1=4 x2=5 (14)x2+19x+90=0 答案：x1=-10 x2=-9 (15)x2-25x+156=0 答案：x1=13 x2=12 (16)x2-22x+57=0 答案：x1=3 x2=19 (17)x2-5x-176=0 答案：x1=16 x2=-11 (18)x2-26x+133=0 答案：x1=7 x2=19 (19)x2+10x-11=0 答案：x1=-11 x2=1 (20)x2-3x-304=0 答案：x1=-16 x2=19 (21)x2+13x-140=0 答案：x1=7 x2=-20 (22)x2+13x-48=0 答案：x1=3 x2=-16 (23)x2+5x-176=0 答案：x1=-16 x2=11 (24)x2+28x+171=0 答案：x1=-9 x2=-19 (25)x2+14x+45=0 答案：x1=-9 x2=-5 (26)x2-9x-136=0 答案：x1=-8 x2=17 (27)x2-15x-76=0 答案：x1=19 x2=-4 (28)x2+23x+126=0 答案：x1=-9 x2=-14 (29)x2+9x-70=0 答案：x1=-14 x2=5 (30)x2-1x-56=0 答案：x1=8 x2=-7 (31)x2+7x-60=0 答案：x1=5 x2=-12 (32)x2+10x-39=0 答案：x1=-13 x2=3 (33)x2+19x+34=0 答案：x1=-17 x2=-2 (34)x2-6x-160=0 答案：x1=16 x2=-10 (35)x2-6x-55=0 答案：x1=11 x2=-5 (36)x2-7x-144=0 答案：x1=-9 x2=16 (37)x2+20x+51=0 答案：x1=-3 x2=-17 (38)x2-9x+14=0 答案：x1=2 x2=7 (39)x2-29x+208=0 答案：x1=16 x2=13 (40)x2+19x-20=0 答案：x1=-20 x2=1 (41)x2-13x-48=0 答案：x1=16 x2=-3 (42)x2+10x+24=0 答案：x1=-6 x2=-4 (43)x2+28x+180=0 答案：x1=-10 x2=-18 (44)x2-8x-209=0 答案：x1=-11 x2=19 (45)x2+23x+90=0 答案：x1=-18 x2=-5 (46)x2+7x+6=0 答案：x1=-6 x2=-1 (47)x2+16x+28=0 答案：x1=-14 x2=-2 (48)x2+5x-50=0 答案：x1=-10 x2=5 (49)x2+13x-14=0 答案：x1=1 x2=-14 (50)x2-23x+102=0 答案：x1=17 x2=6 (51)x2+5x-176=0 答案：x1=-16 x2=11 (52)x2-8x-20=0 答案：x1=-2 x2=10 (53)x2-16x+39=0 答案：x1=3 x2=13 (54)x2+32x+240=0 答案：x1=-20 x2=-12 (55)x2+34x+288=0 答案：x1=-18 x2=-16 (56)x2+22x+105=0 答案：x1=-7 x2=-15 (57)x2+19x-20=0 答案：x1=-20 x2=1 (58)x2-7x+6=0 答案：x1=6 x2=1 (59)x2+4x-221=0 答案：x1=13 x2=-17 (60)x2+6x-91=0 答案：x1=-13 x2=7 (61)x2+8x+12=0 答案：x1=-2 x2=-6 (62)x2+7x-120=0 答案：x1=-15 x2=8 (63)x2-18x+17=0 答案：x1=17 x2=1 (64)x2+7x-170=0 答案：x1=-17 x2=10 (65)x2+6x+8=0 答案：x1=-4 x2=-2 (66)x2+13x+12=0 答案：x1=-1 x2=-12 (67)x2+24x+119=0 答案：x1=-7 x2=-17 (68)x2+11x-42=0 答案：x1=3 x2=-14 (69)x20x-289=0 答案：x1=17 x2=-17 (70)x2+13x+30=0 答案：x1=-3 x2=-10 (71)x2-24x+140=0 答案：x1=14 x2=10 (72)x2+4x-60=0 答案：x1=-10 x2=6 (73)x2+27x+170=0 答案：x1=-10 x2=-17 (74)x2+27x+152=0 答案：x1=-19 x2=-8 (75)x2-2x-99=0 答案：x1=11 x2=-9 (76)x2+12x+11=0 答案：x1=-11 x2=-1 (77)x2+17x+70=0 答案：x1=-10 x2=-7 (78)x2+20x+19=0 答案：x1=-19 x2=-1 (79)x2-2x-168=0 答案：x1=-12 x2=14 (80)x2-13x+30=0 答案：x1=3 x2=10 (81)x2-10x-119=0 答案：x1=17 x2=-7 (82)x2+16x-17=0 答案：x1=1 x2=-17 (83)x2-1x-20=0 答案：x1=5 x2=-4 (84)x2-2x-288=0 答案：x1=18 x2=-16 (85)x2-20x+64=0 答案：x1=16 x2=4 (86)x2+22x+105=0 答案：x1=-7 x2=-15 (87)x2+13x+12=0 答案：x1=-1 x2=-12 (88)x2-4x-285=0 答案：x1=19 x2=-15 (89)x2+26x+133=0 答案：x1=-19 x2=-7 (90)x2-17x+16=0 答案：x1=1 x2=16 (91)x2+3x-4=0 答案：x1=1 x2=-4 (92)x2-14x+48=0 答案：x1=6 x2=8 (93)x2-12x-133=0 答案：x1=19 x2=-7 (94)x2+5x+4=0 答案：x1=-1 x2=-4 (95)x2+6x-91=0 答案：x1=7 x2=-13 (96)x2+3x-4=0 答案：x1=-4 x2=1 (97)x2-13x+12=0 答案：x1=12 x2=1 (98)x2+7x-44=0 答案：x1=-11 x2=4 (99)x2-6x-7=0 答案：x1=-1 x2=7 (100)x2-9x-90=0 答案：x1=15 x2=-6 (101)x2+17x+72=0 答案：x1=-8 x2=-9 (102)x2+13x-14=0 答案：x1=-14 x2=1 (103)x2+9x-36=0 答案：x1=-12 x2=3 (104)x2-9x-90=0 答案：x1=-6 x2=15 (105)x2+14x+13=0 答案：x1=-1 x2=-13 (106)x2-16x+63=0 答案：x1=7 x2=9 (107)x2-15x+44=0 答案：x1=4 x2=11 (108)x2+2x-168=0 答案：x1=-14 x2=12 (109)x2-6x-216=0 答案：x1=-12 x2=18 (110)x2-6x-55=0 答案：x1=11 x2=-5 (111)x2+18x+32=0 答案：x1=-2 x2=-16【精品文档】第 16 页
展开阅读全文