**First-year decline in value deductions (FY2025-26)**

**(a) Prime cost method**  
$30,000 × (1 / 5) = **$6,000**

**(b) Diminishing value method**  
$30,000 × (2 / 5) = **$12,000**

**Controlling authority**  
Division 40 of the *Income Tax Assessment Act 1997* (ITAA 1997).