Write Using Negative Exponents x^4-x^3

$x^{4} - x^{3}$

Move $x^{4}$ in $\frac{x^{4}}{1}$ to the denominator and change the exponent from positive to negative.

$\frac{1}{x^{- 4}}$

Move $x^{3}$ in $\frac{- x^{3}}{1}$ to the denominator and change the exponent from positive to negative.

$\frac{- 1}{x^{- 3}}$

Rewrite the expression with the negative exponents.

$\frac{1}{x^{- 4}} + \frac{- 1}{x^{- 3}}$