5 * (2/3)³ : (4/9)² =  7 1/2,

1) (2/3)³ = 8/27,

2) (4/9)² = 16/81,

3) 5 * 8/27 = 40/27,

4) 40/27 : 16/81 = 40/27 * 81/16 = 15/2 = 7 1/2