(1)2x^2-4x-5=0 (2)-3x²-4x+4=0 (3)3x(x-1)=2-2x (4)(x-1)(x+2)=70 (5)x(x+6(1)2x^2-4x-5=0(2)-3x²-4x+4=0(3)3x(x-1)=2-2x(4)(x-1)(x+2)=70(5)x(x+6)=7(6)(3-x)²+x²=9详细过程………………
来源:学生作业帮助网 编辑:六六作业网 时间:2024/12/23 06:50:46
(1)2x^2-4x-5=0 (2)-3x²-4x+4=0 (3)3x(x-1)=2-2x (4)(x-1)(x+2)=70 (5)x(x+6(1)2x^2-4x-5=0(2)-3x²-4x+4=0(3)3x(x-1)=2-2x(4)(x-1)(x+2)=70(5)x(x+6)=7(6)(3-x)²+x²=9详细过程………………
(1)2x^2-4x-5=0 (2)-3x²-4x+4=0 (3)3x(x-1)=2-2x (4)(x-1)(x+2)=70 (5)x(x+6
(1)2x^2-4x-5=0
(2)-3x²-4x+4=0
(3)3x(x-1)=2-2x
(4)(x-1)(x+2)=70
(5)x(x+6)=7
(6)(3-x)²+x²=9
详细过程……………………………………急!
(1)2x^2-4x-5=0 (2)-3x²-4x+4=0 (3)3x(x-1)=2-2x (4)(x-1)(x+2)=70 (5)x(x+6(1)2x^2-4x-5=0(2)-3x²-4x+4=0(3)3x(x-1)=2-2x(4)(x-1)(x+2)=70(5)x(x+6)=7(6)(3-x)²+x²=9详细过程………………
(1)2x²-4x-5=0
x²-2x+1=1+5/2
(x-1)²=14/4
x-1=±√14/2
∴x=(2+√14)/,
或x=(2-√14)/2.
(2)-3x²-4x+4=0
3x²+4x-4=0
(x+2)(3x-2)=0
x=-2或x=2/3.
(3)3x(x-1)=2-2x
3x(x-1)+2(x-1)=0
(x-1)(3x+2)=0
x=1或x=-2/3.
(4)(x-1)(x+2)=70
x²+x-72=0
(x-8)(x+9)=0
x=8或x=-9.
(5)x(x+6)=7
x²+6x-7=0
(x-1)(x+7)=0
x=1或x=-7.
(6)(3-x)²+x²=9
(3-x)²-(3+x)(3-x)=0
(3-x)[(3-x)-(3+x)]=0
2x(x-3)=0
x=0或x=3.
牛B啊!我们初二才学一元二次方程,你们6年级就学了!