(x+1)(x-4)-(x-5)(x-1)=x²-4x+x-4-(x²-x-5x+5)=x²-4x+x-4-x²+x+5x-5=3x-9=0所以x=3
先把式子展开。(x+1)(x-4)-(x-5)(x-1)=0x^2-3x-4-(x^2-6x+5)=03X=9X=3
(x+1)(x-4)-(x-5)(x-1)=0x^2-3x-4-(x^2-6x+5)=0x^2-3x-4-x^2+6x-5=0x^2-x^2+6x-3x-4-5=03x-9=0x=3
原式=(x