-3x²-2x+4=03x²+2x-4=03(x²+2/3x)=43(x²+2/3x+1/9)=4+1/33(x+1/3)²=13/3(x+1/3)²=13/9x+1/3=±√13/3解得x=(√13-1)/3或x=-(√13+1)/3x²+2x-99=0x²+2x+1=100(x+1)²=10...