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
2020-01-04
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
优质解答
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...
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...