(1)3X²+5（2x+1)=0 3X²+10x+5=0x=[-10±√(10²-4*3*5)]/(2*3)=(-5±√10)/3 (2)x²+2(√2-1)x+3-2√2=0x={-2(√2-1)±√[2²(√2-1)²-4(3-2√2)]}/2=-2(√2-1)
