内容正文:
第二十一章一元二次方程解方程专项训练
(1)-3x2+22x-24=0.(公式法)
(7)x+5=x2-25.
(2)7xx-3)=3x-9;
(8)(x-5-36=0:
(3)x2-5x+5=0.
(9)x2-2x-8-0.
(4)x2-6x+8=0:
(10)x2-2x-1=05
(5)2x+6=(x+3).
(11)(x-3)-4x3-x=0:
(6)2x2-7x+3=0:
(12)2x2-7x-2=0:
(彩围出)E-=x-x(忆)
(I-x)=(1-x)x (81)
·xL=E+xZ(Z)
8t=x9-xE (LI)
:0=t-l-17(⑦z)
(x-Es=,E-x)(9I)
t0=6-x8+r(IZ)
-x=(I-xZ)(SI)
:0=S-x-x (0)
0=I-x+x()
-x=(-x)xE (61)
0=(E-x)1+xz)(E1)
E
0=t-(Z-x)(9E)
40=b-x+x(0)
(I+x)(I-x)=(E-x)x (SE)
x-9=(-x)(6)
·0=9-xZ+r(e)
0=8--xg)
(8)
0=S-x+E(EE)
0=Z1+xII-x乙(LZ)
(Z+x)=9+xE(E)
1-xE=1-x(9z)
(I+x)8=s1+(I+x)(IE)
(张严7出)0=【-x-x(7)
(37)x2-6x-7=0
(38)2x2-4x-1=0(公式法);
4
参考答案
0=65
3
(2)=76=3
3)5=5+5
2
5=6+5
(4)x1=2,x2=4
(5)x1=-3,x2=-1
(6)x=3;6=2
1
(7)x=6,x2=-5
(8)x=11,x2=-1
(9)=4,x3=-2
(10)x=1+2,x=1-2
3
1)x=亏6=3
12)x1+6⑤.51-@
4
4
55=分3
(14)x=-1+2,x,=-1-2
55-
3
(16)x1=-2,x1=3
(17)x1=1+7,x,=1-17
(18)x=2,=2
1
(19)=3”为=4
(20)x1=5,x2=-1
(21)x=1,x2=-9
1
(22)1=4,6=-2
23》=6月
(24)x1=3,2=1
(25)x=1+5
2
(26)x=1,x1=2:
3
(2)x=26=4,
》5专
(29)5=3+1☑
。3-7
2
2
(30)5=-1+7
2
5=而
2
(31)x=1,6=2
(32)x,=-2,2=1
(33)x=-1+v6
2
2
(34)x,=-1+万,,=-1-万
(35)x=3+22,x1=3-2V2
(36)=4,x2=0
(37)x=7,x2=-1
(38)x=2+V6
2-6
25=
2
3