Question

观察下列各式：1/6=1/2.3=1/2-1/3;1/12=1/3.4=1/3-1/4;1/20=1/4.5=1/4-1

Answer 1

1/（x-3)- 1/（x-2)- 1/(x-1)(x-3)+ 1/(x-2)- 1/(x-1)=-1

1/（x-3)- 1/(x-1)(x-3)- 1/(x-1)=-1

2/(x-1)（x-3)- 1/(x-1)(x-3)=-1

1/(x-1)(x-3)=-1

(x-1)(x-3)=-1

x^2-4x+3=-1

x^2-4x+4=0

(x-2)^2=0

x=2