Question

Which is the simplified form of

Answer 1

For this case we have that by definition of power properties:

$a ^ {- 1} = \frac {1} {a ^ 1} = \frac {1} {a}$

We have the following expression:

$r^{-7} + s ^{-12}$

We can rewrite it as:

$\frac {1} {r ^ 7} + \frac {1} {s ^{ 12}}$

Finally:

$r ^ {- 7} + s ^ {- 12} = \frac {1} {r ^ 7} + \frac {1} {s ^ {12}}$

Answer:

Option D

Answer 2

Answer: $\frac{1}{r^{7} } +\frac{1}{s^{12} }$

Step-by-step explanation:

With negative powers, $r^{-7} = \frac{1}{r^{7} }$

do the same for s too