【(x+1)(x+4)】【(x+2)(x+3)】-8=0(x²+5x+4)(x²+5x+6)-8=0(x²+5x)²+10(x²+5x)+24-8=0(x²+5x)²+10(x²+5x)+16=0(x²+5x+2)(x²+5x+8)=0x²+5x+2=0x=(-5±√12)/2x²+5x+8=0无实数解