Final answer:
The taxpayer must report the net gain of $7,000 from gambling as income on his tax return, which is the difference between his winnings and losses. The statement is true.
Step-by-step explanation:
The question poses a scenario where a taxpayer has experienced both losses and gains from gambling. On the first night, the taxpayer lost $5,000 and on the second night, he won $12,000. When filing a tax return, the taxpayer can only report the net gambling earnings. Therefore, the statement that the taxpayer only needs to report $7,000 as income on his tax return is true, as the net income is calculated by subtracting the losses from the winnings ($12,000 - $5,000 = $7,000).