Is this the fifth question?
In this problem, you simplify the fraction in lim and finally become
lim(- 1/((x-2)*(x-3))
Finally, x= 1 is brought into use.
The result is-1/2, choose a.
The first formula in brackets becomes: 1/((x- 1)(x-2)).
The second formula is: 2/((x- 1)(x-3))
Then divide it! Don't separate the factors of simplification! Make sure the simplification is correct!
Then the above formula can appear!