(5³)⁻¹ * (7³)⁻² / (5²)⁻¹ * (7²)⁻⁴ = ((5)⁻³ / (5⁻²)) * ((7)⁻⁶ / (7⁻⁸)) = 5⁻¹ * 7² = 1/5 * 49 = 49/5 = 5 4/5