用配方法做 6x²—7x+1=o 5x²-18=9x 4x²-3x=52 5x²=4-2x

6x²-7x+1=06(x²-7/6x+49/144)-6*49/144+1=06(x-7/12)²=150/144(x-7/12)²=25/144x-7/12=±5/12x=7/12±5/12x=1或x=1/65x²-18=9x5x²-9x-18=05(x²-9/5x+81/100)-5*81/100-18=05(x-9...