The addition of the expression 5/(x² – 9) and 3/(x + 3) is (5x – 12)/[(x + 3)(x – 3)]. Then the correct option is D.
A fraction number is a number that represents the part of the whole, where the whole can be any number. It is in the form of numerator and denominator.
The expressions are given below.
[tex]\rm \dfrac{3}{x^2 - 9} \ and \ \dfrac{5}{x+3}[/tex]
The sum of the expressions will be
[tex]\rm \dfrac{3}{x^2 - 9} + \dfrac{5}{x+3}[/tex]
We know that the formula
a² – b² = (a + b)(a – b)
Then we have
[tex]\rm \dfrac{3}{x^2 - 3^2} + \dfrac{5}{x+3}\\\\\\\rm \dfrac{3}{(x-3)(x+3)} + \dfrac{5}{x+3}\\\\\\\rm \dfrac{3+5(x-3)}{(x-3)(x+3)} \\\\\\\dfrac{3+5x-15}{(x-3)(x+3)} \\\\\\\dfrac{5x-12}{(x-3)(x+3)}[/tex]
The addition of the expression 5/(x² – 9) and 3/(x + 3) is (5x – 12)/[(x + 3)(x – 3)]. Then the correct option is D.
More about the fraction number link is given below.
https://brainly.com/question/78672