Which expression shows the most efficient first step to simplify $\frac{5}{9} + \frac{1}{4} - \frac{2}{9}$ by grouping like fractions?

$(\frac{5}{9} - \frac{2}{9}) + \frac{1}{4}$

$(\frac{5}{9} + \frac{1}{4}) - \frac{2}{9}$

$\frac{5}{9} - (\frac{1}{4} + \frac{2}{9})$

$\frac{1}{4} + (\frac{2}{9} - \frac{5}{9})$

When you reorder $\frac{1}{2} + \frac{5}{7} - \frac{3}{7}$ to become $(\frac{5}{7} - \frac{3}{7}) + \frac{1}{2}$, which mathematical properties are being applied?

Commutative and Associative Properties

Identity and Inverse Properties

Multiplication Property of Equality