if (5x+1)>= 0, 6x-2 = 5x +1, x=3, OKif 3(x-1)<= 0, -6x+2 = -(5x +1), x=3, not a true rootif 3(x-1)<=0<= (5x+1), 6x-2 = -(5x +1), x = 1/11, oktaken togetherx =3 or x = 1/11
两边平方,最后解得X=3或1/11