Which piecewise function best represents a tax system where the first $⁢10,000 of income is taxed at 8% , and any income above $⁢10,000 is taxed at 20% ?

For income up to $10,000, the tax is 8% of income, so T(x) = 0.08x. At $10,000, that tax equals $800. For income above $10,000, the taxpayer still owes that $800, plus 20% of the amount above $10,000: 800 + 0.2(x − 10,000). This is choice D.

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