The first step for solving this expression is to write all numerators above the least common denominator. For this problem,, our least common denominator will be (x - 3) × (x - 4). 

Now we will distribute 2x through the first set of parenthesis.

Distribute -4x through the second set of parenthesis.

Multiply the two parentheses in the denominator of the fraction together.

Collect the like terms with a variable of x² on the numerator (top) of the fraction.

Collect the terms on the numerator of the fraction with a variable of x. 

Lastly,, collect the terms with an x variable on the denominator (bottom) of the fraction to get your final answer. 

Let me know if you have any further questions.
:)