Respuesta :

Answer:

 1           1

------ + -------    

r^7      s^12

Step-by-step explanation:

r^(-7) + s^(-12) can be re-written as

 1           1

------ + -------    by putting to use the rule:

r^7      s^12

                1

x^(-a) = ----------

              x^a

For this case, we must simplify the following expression:

[tex]r ^ {- 7} + s ^ {- 12}[/tex]

By definition of power properties we have to:

[tex]a ^ {- 1} = \frac {1} {a ^ 1} = \frac {1} {a}[/tex]

So, rewriting the expression we have:

[tex]\frac {1} {r ^ 7} + \frac {1} {s ^ {12}}[/tex]

Answer:

[tex]\frac {1} {r ^ 7} + \frac {1} {s ^ {12}}[/tex]

Option D