hi there, trying to understand this expression.
$\displaystyle 5^{4-x}$
is the same as:
$\displaystyle
= (\frac{1}{5})^{x-4}
$
im not really understanding what it does to get that. any1 ? thank u
One of the laws of exponents says:
$\displaystyle a^{m}=\left(\frac{1}{a}\right)^{-m} \ \ or \ \ \left(\frac{a}{b}\right)^{-m}=\left(\frac{b}{a}\right)^m$
$\displaystyle 5^{4-x}=\left(\frac{1}{5}\right)^{-(4-x)}=\left(\frac{1}{5}\right)^{(-4+x)}=\left(\frac{1}{5}\right)^{(x-4)}$