Select the correct answer.

Assuming that no denominator equals zero, what is the simplest form of this expression?

[tex]\[ \frac{x-1}{x^2-4x+3} \div \frac{5x-2}{x^2-9} \][/tex]

A. [tex]\[ \frac{1}{5x-2} \][/tex]

B. [tex]\[ \frac{3}{5x-2} \][/tex]

C. [tex]\[ \frac{x-1}{x+3} \][/tex]

D. [tex]\[ \frac{x+3}{5x-2} \][/tex]



Answer :

To find the simplest form of the given expression

[tex]\[ \frac{x-1}{x^2-4 x+3} \div \frac{5 x-2}{x^2-9} \][/tex]

we need to follow several steps, including simplification and performing the division of fractions. Here is the detailed, step-by-step process:

1. Factorize the Denominators:

Let's first factorize the denominators of the fractions.

The denominator of the first fraction is [tex]\( x^2 - 4x + 3 \)[/tex]:
[tex]\[ x^2 - 4x + 3 = (x - 1)(x - 3) \][/tex]

The denominator of the second fraction is [tex]\( x^2 - 9 \)[/tex]:
[tex]\[ x^2 - 9 = (x + 3)(x - 3) \][/tex]

2. Rewrite the Expression with Factorized Denominators:

Rewrite the given expression using the factorized forms:
[tex]\[ \frac{x-1}{(x - 1)(x - 3)} \div \frac{5x - 2}{(x + 3)(x - 3)} \][/tex]

3. Simplify the Division of Fractions:

To divide by a fraction, multiply by its reciprocal:
[tex]\[ \frac{x-1}{(x - 1)(x - 3)} \cdot \frac{(x + 3)(x - 3)}{5x - 2} \][/tex]

Now, simplify by canceling out common factors. Notice that [tex]\((x - 1)\)[/tex] and [tex]\((x - 3)\)[/tex] appear in the numerator and denominator:
[tex]\[ = \frac{(x-1) \cdot (x + 3)(x - 3)}{(x - 1)(x - 3) \cdot (5x - 2)} \][/tex]

Cancel the common terms [tex]\((x - 1)\)[/tex] and [tex]\((x - 3)\)[/tex] from the numerator and the denominator:
[tex]\[ = \frac{x + 3}{5x - 2} \][/tex]

So the simplest form of the given expression is:
[tex]\[ \frac{x + 3}{5x - 2} \][/tex]

This matches the fourth option provided. Thus, the correct answer is:

[tex]\[ \boxed{\frac{x+3}{5 x-2}} \][/tex]