Question

1 in the united states, the authority to levy an income tax lies within the
constitution of the united states.
10th amendment to the u.s. constitution.
internal revenue service.
office of the u.s. president.
2 taxable income, tax deductions, exemptions, and expenses are defined by the
tax laws as passed by congress and signed into law by the u.s. president.
income tax laws passed in 1913.
tax laws that are passed by the internal revenue service.
16th amendment to the u.s. constitution.

Explanation:

1. The 16th Amendment to the U.S. Constitution gave Congress the power to levy an income tax. The Constitution (original) had limitations on direct taxes. The 10th Amendment is about reserved powers to states. The Internal Revenue Service (IRS) administers taxes, it doesn't have the authority to levy. The President doesn't have the sole authority to levy income tax.
2. Tax - related definitions like taxable income, deductions etc. are set by tax laws passed by Congress (as per the legislative power) and signed by the President (executive action). The 1913 income tax laws were enabled by the 16th Amendment. The IRS enforces tax laws, it doesn't define these fundamental tax terms. The 16th Amendment gave the power to levy income tax, but the detailed definitions come from the laws passed by Congress and signed by the President.

Answer:

1. Constitution of the United States (specifically the 16th Amendment).
2. tax laws as passed by Congress and signed into law by the U.S. president.