4

Set 6: Exponential Functions

Explanation

Answer: A

Solve: ex+3=e2x1e^{x+3} = e^{2x-1}

A.

x=4x = 4

✓ Correct
B.

x=2x = 2

C.

x=1x = -1

D.

x=3x = 3

Detailed Explanation

Choice A is correct. Choice A is the correct answer. Equal bases means equal exponents. 1. Given: ex+3=e2x1e^{x+3} = e^{2 x-1}. 2. Equal bases: x+3=2x1x + 3 = 2 x - 1. 3. Solve: 3+1=2xx3+ 1 = 2 x - x, so x=4x = 4. 4. Verify: e4+3=e7e^{4+3} = e^7 and e2(4)1=e7e^{2(4)-1} = e^7 ✓ Strategic Tip: When bases match, set exponents equal. Choice B is incorrect because e5e3e^5 \neq e^3. Choice C is incorrect because e2e3e^2 \neq e^{-3}. Choice D is incorrect because e6e5e^6 \neq e^5.

Key Steps:

The correct answer is x=4x = 4

Why others are wrong:
B: Choice B is incorrect and may result from a calculation error.
C: Choice C is incorrect and may result from a calculation error.
D: Choice D is incorrect and may result from a calculation error.

🎯 Keep Practicing!

Master all sections for your best SAT score