几道很简单的初二一元二次方程,
问题描述:
几道很简单的初二一元二次方程,
1.x方-2mx+m方-n方=0
2.x方+3a方=4ax-2a+1
3.x方+mx+n=0
4.(x方+3x)方-2(x方+3)-8=0
5.a方(x方-x+1)-a(x方-1)=(a方-1)x
6.6x方-3倍根号3x=2根号2x-根号6
(X不是在根号里面 是乘的关系)
答
1.x^2-2mx+m^2-n^2=0
(x-m-n)(x-m+n)=0
x1=m+n,x2=m-n
2.x^2+3a^2=4ax-2a+1
x^2-4ax+3a^2+2a-1=0
(x-2a)^2-(a-1)^2=0
(x-2a+a-1)(x-2a-a+1)=0
x1=a+1,x2=3a-1
3.x^2+mx+n=0
x1=[-m+√(m^2-4n)]/2
x2=[-m-√(m^2-4n)]/2
4.(x^2+3x)^2-2(x^2+3)-8=0
(x^2+3x-4)(x^2+3x+2)=0
(x+4)(x-1)(x+1)(x+2)=0
x1=-4,x2=1,x3=-1,x4=-2
5.a^2(x^2-x+1)-a(x^2-1)=(a^2-1)x
(a^2-a)x^2+(1-2a^2)x+a^2+a=0
a(a-1)x^2+(1-2a^2)x+a(a+1)=0
[ax-(a+1)]*[(a-1)x-a]=0
x1=1+1/a,x2=-1-1/(a-1)
6.6x^2-3√3 x=2√2 x-√6
6x^2-(2√2+3√3) x+√6=0
(2x-√3)(3x-√2)=0
x1=(√3)/2,x2=(√2)/3