1-x分之3-x+x的平方-8x+7分之x的平方-2=1+ 7-x分之5-x
(x-3)/(x-1)+(x²-2)/[(x-7)(x-1)]=1+(x-5)/(x-7)
平方同乘以(x-1)(x-7)得：
(x-3)(x-7)+x²-2=(x-1)(x-7)+(x-5)(x-1)
x²-10x+21+x²-2=x²-8x+7+x²-6x+5
4x=-7
x=-7/4