一元二次方程的解法吧ax^2+bx+c=0(a/=0)1.直接开平方法eg:(2x-1)^2=12x-1=+-12x-1=1or2x-1=-12x=2or2x=0x=1orx=02.因式分解法:x^2-2x-3=0(x-3)(x+1)=0x1=3,x2=-13.配方法x^2-x-2=0(x-1/2）^2-1/4-2=0(x-1/2)^2=9/4x-...