AP® Precalculus · Free response

An equation quadratic in e to the x, and single-term forms

write it first, then score yourself point by point

Q4: Symbolic Manipulations · Part B: no calculator · 6 points

The question

Name: ______________________   Date: ____________   An equation quadratic in e to the x, and single-term forms (6 points)

No calculator. Give exact values and show the work that leads to each answer.

  1. (A(i)) Solve e2x−3ex−10=0e^{2x} - 3e^x - 10 = 0 for xx. [1 point]

  2. (A(ii)) Explain why the other factor in part A(i) gives no solution. [1 point]

  3. (B(i)) Rewrite 8x+14x\frac{8^{x + 1}}{4^x} as a single power of 22. [1 point]

  4. (B(ii)) Rewrite ln⁡(x2−9)−ln⁡(x+3)\ln(x^2 - 9) - \ln(x + 3) as a single natural logarithm with no fraction, for x>3x > 3. [1 point]

  5. (C) Solve 4x−6⋅2x+8=04^x - 6 \cdot 2^x + 8 = 0 for xx. [2 points]