Question

Simplify 25^ - 1/2 Please explain! I know the answer is 1/5 but why?

Answer 1

$(25)^{-\frac{1}{2} }$

When the exponent is negative, you have to make the number a fraction(1 over the number).

For example:

$25^{-2} = \frac{1}{25^{2} }$

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

This gets rid of the negative, but it leaves the exponent

$(25)^{-\frac{1}{2}} = \frac{1}{25^{1/2}}$

When an exponent is a fraction, it is the square root.

For example:

$x^{\frac{1}{3}} = \sqrt[3]{x}$

$x^{\frac{1}{2}} =\sqrt{x}$

$x^{\frac{1}{4}}=\sqrt[4]{x}$

So...

$\frac{1}{25^{1/2}} = \frac{1}{\sqrt{25} } = \frac{1}{5}$