## Algebra: A Combined Approach (4th Edition)

$\frac{3}{64}$
1. Take the reciprocal of both fractions due to negative exponents which will give you $\frac{1}{4^2}-\frac{1}{4^3}$ 2. Find the least common denominator to add the fractions which will give you $\frac{4}{64}-\frac{1}{64}$ 3. Subtract the fractions which will give you $\frac{3}{64}$