Answer :

To simplify the given expression [tex]\(\frac{1}{x^2-5x+6} + \frac{2}{4x-x^2-3}\)[/tex], let's break it down step-by-step and combine the fractions appropriately.

Step 1: Factorize the denominators of both fractions.
- For [tex]\(x^2 - 5x + 6\)[/tex]:
[tex]\[ x^2 - 5x + 6 = (x - 2)(x - 3) \][/tex]
- For [tex]\(4x - x^2 - 3\)[/tex]:
[tex]\[ 4x - x^2 - 3 = - (x^2 - 4x + 3) = - ((x-1)(x-3)) \][/tex]

Now the expression looks like:
[tex]\[ \frac{1}{(x-2)(x-3)} + \frac{2}{-(x-1)(x-3)} \][/tex]

Step 2: Adjust the signs to combine under a common denominator:
[tex]\[ \frac{1}{(x-2)(x-3)} - \frac{2}{(x-1)(x-3)} \][/tex]

Step 3: Determine the common denominator, which is [tex]\((x-2)(x-3)(x-1)\)[/tex]:
[tex]\[ \frac{(x-1) \cdot 1 - 2 \cdot (x-2)}{(x-2)(x-3)(x-1)} \][/tex]

Step 4: Simplify the numerator:
[tex]\[ (x-1) - 2(x-2) = x - 1 - 2x + 4 = -x + 3 \][/tex]

So, the expression becomes:
[tex]\[ \frac{-x + 3}{(x-2)(x-3)(x-1)} \][/tex]

Step 5: Notice that [tex]\(-x + 3\)[/tex] can be written as [tex]\(-(x - 3)\)[/tex], hence:
[tex]\[ \frac{-(x - 3)}{(x-2)(x-3)(x-1)} \][/tex]

Cancelling the common [tex]\((x - 3)\)[/tex] term in the numerator and denominator, we get:
[tex]\[ \frac{-1}{(x-2)(x-1)} \][/tex]

Therefore, the simplified form of the given expression is:
[tex]\[ \boxed{\frac{-1}{(x^2 - 3x + 2)}} \][/tex]

This is the simplified form of the given expression as required.