Select the correct answer.

What is the simplest form of this expression?
[tex]\[ \frac{x-3}{x-1} + \frac{6}{x-3} \][/tex]

A. [tex]\[ \frac{x^2 + 3}{(x-1)(x-3)} \][/tex]

B. [tex]\[ \frac{x + 3}{(x-1)(x-3)} \][/tex]

C. [tex]\[ \frac{x^2 + 12x + 15}{(x-1)(x-3)} \][/tex]

D. [tex]\[ \frac{x^2 - 6x + 3}{(x-1)(x-3)} \][/tex]



Answer :

To simplify the expression [tex]\(\frac{x-3}{x-1}+\frac{6}{x-3}\)[/tex], let's follow a detailed, step-by-step process.

1. Find a common denominator:
The denominators of the fractions are [tex]\(x-1\)[/tex] and [tex]\(x-3\)[/tex]. The common denominator is [tex]\((x-1)(x-3)\)[/tex].

2. Rewrite each fraction with the common denominator:
[tex]\[ \frac{x-3}{x-1} = \frac{(x-3)(x-3)}{(x-1)(x-3)} \][/tex]
[tex]\[ \frac{6}{x-3} = \frac{6(x-1)}{(x-1)(x-3)} \][/tex]

3. Combine the fractions into a single fraction:
[tex]\[ \frac{(x-3)(x-3) + 6(x-1)}{(x-1)(x-3)} \][/tex]

4. Expand and simplify the numerator:
First, expand [tex]\((x-3)(x-3)\)[/tex]:
[tex]\[ (x-3)(x-3) = x^2 - 6x + 9 \][/tex]

Then, expand [tex]\(6(x-1)\)[/tex]:
[tex]\[ 6(x-1) = 6x - 6 \][/tex]

Combine these results in the numerator:
[tex]\[ x^2 - 6x + 9 + 6x - 6 \][/tex]

Simplify the numerator by combining like terms:
[tex]\[ x^2 - 6x + 6x + 9 - 6 = x^2 + 3 \][/tex]

5. Write the simplified form of the fraction:
[tex]\[ \frac{x^2 + 3}{(x-1)(x-3)} \][/tex]

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

Therefore, the correct answer is:
A. [tex]\(\frac{x^2+3}{(x-1)(x-3)}\)[/tex]