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Solve for x: 4^x - 3 * 2^(x+3) + 128 = 0.
- x = 3 or x = 4
- x = 3 only
- x = 4 only
- x = 2 or x = 5
Correct answer: x = 3 or x = 4
Solution
Reduce the exponential equation to a quadratic in t = 2^x, solve it, then convert each root back to x using logarithms base 2.
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