3x^2-4x-1=0

问题描述:

3x^2-4x-1=0
因式分解法

3x²-4x-1=0x²-4x/3-1/3=0x²-4x/3+(2/3)²-4/9-1/3=0(x-2/3)²-7/9=0(x-2/3)²-(√7/3)²=0(x-2/3+√7/3)(x-2/3-√7/3)=0x-2/3+√7/3=0或x-2/3-√7/3=0x1=(2-√7)/3   x2=(...