关于X的一元二次方程M X的平方+(3M+2)X + 2M +2=0怎么解
问题描述:
关于X的一元二次方程M X的平方+(3M+2)X + 2M +2=0怎么解
答
mx²-(3m+2)x+2m+2=0
x²-(3m+2)x/m+(2m+2)/m=0
x²-(3m+2)x/m=-(2m+2)/m
x²-(3m+2)x/m+(3m+2)²/(4m²)=(3m+2)²/(4m²)-4m(2m+2)/(4m²)
(x-3m+2)²=(9m²+12m+4)/(4m²)-(8m²+8m)/(4m²)
(x-3m+2)²=(9m²+12m+4-8m²-8m)/(4m²)
(x-3m+2)²=(m²+4m+4)/(4m²)
(x-3m+2)²=(m+2)²/(4m²)
x-3m+2=±(m+2)/(2m)
x=[3m+2±(m+2)]/(2m)
x1=(3m+2+m+2)/(2m)=(4m+4)/(2m)=(2m+2)/m
x2=(3m+2-m-2)/(2m)=(2m)/(2m)=1
答
mx²+(m+2m+2)x+2m+2=0
mx²+mx+(2m+2)x+(2m+2)=0
mx(x+1)+(2m+2)(x+1)=0
(x+1)[mx+(2m+2)]=0
一元二次方程则m≠0
所以
x=-1,x=-(2m+2)/m