解一元二次方程(过程和答案都要)2⑴.X+2X-3=0 2⑵.X-2X-3=02⑶.X+2X+1=02⑷.X+2X+3=02⑸.X+2X-2=02⑹.2X+X-3=0
问题描述:
解一元二次方程(过程和答案都要)
2
⑴.X+2X-3=0
2
⑵.X-2X-3=0
2
⑶.X+2X+1=0
2
⑷.X+2X+3=0
2
⑸.X+2X-2=0
2
⑹.2X+X-3=0
答
1.3X=3 X=1
2.-1X=3 X=-3
3.3X=-1 X=-1/3
4.3X=-3 X=-1
5.3X=2 X=2/3
6.3X=3 X=1
是我看错题了吗?
答
1.-3 ,1
2.-1,3
3,-1
4,无解
5,-1+√3 -1-√3
6.1 -3/2
答
⑴.X²+2X-3=0(x+3)(x-1)=0x=-3或x=1⑵.X²-2X-3=0 (x-3)(x+1)=0x=3或x=-1⑶.X²+2X+1=0 (x+1)²=0x=-1⑷.X²+2X+3=0 (x+1)²+2=0因为(x+1)²>=0,2>0所以一定有(x+1)²+2>0,原...