设未知数为x显然,a b是一元二次方程3x²+5x-1=0的两个解.3x²+5x-1=03(x²+5/3x-1/3)=03(x²+5/3x+25/36-25/36-1/3)=03[(x+5/6)²-37/36]=0两边乘以1/3(x+5/6)²-37/36=0(x+5/6)²=37/3...给个采纳啊嗯嗯