Cabinet Decision No. 39 of 2019, Article 5, provides detailed instructions for calculating gross and taxable income. It specifies that capital gains from tangible, intangible, and real estate assets are calculated based on market price or consideration. Deductible expenses must be necessary for the activity, documented, and related to the specific tax year. The article also limits the carry-forward of losses to five years and prohibits the deduction of losses from exempt income sources. This ensures that only legitimate, documented business costs offset the taxpayer's gross revenue.