Question 9 • TX-Precalculus A
Divide both sides of 10,000(4^x) ≥ 320,000 by 10,000 to get 4^x ≥ 32. Since 4^2.5 = 32 and 4^x increases as x increases, the inequality holds for x ≥ 2.5. The interval [2.5, ∞) represents those hours.
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