Simplify the fraction multiplication: (4/7) × (2/3) ÷ (4/7) = ?

Simplify the expression: [9⁻² × 3⁵ × (5⁻²)³] / [(3⁻³)⁴ × 5⁴].

Simplify the decimal expression: (6.25 − 2.23) × (3.35 − 2.23) + (0.0016 − 2.987) =

Simplify: √(9 - 4√5) =

Simplify: (81)⁻¹ × 3⁻⁵ × 3⁹ × 64^(5/6) × (3^(1/3))⁶.

Which of the following fractions is the largest: 4/5, 7/8, 6/7, 5/6?