MCQ practice · SSC Higher Mathematics Board questions · Chapter 9: Exponential and Logarithmic Function
If 3^(2x + 5) = 3·5^(2x + 4), then x = ?
Think it through first, then pick an option.
- a −2
- b −3/2
- c +3/2
- d 2
Answer and explanation
Correct answer: a −2
Dividing by 3 gives 3^(2x+4) = 5^(2x+4); the bases differ, so the exponent 2x + 4 = 0 and x = −2.
Why the other options are wrong
- b −3/2: For x = −3/2, 2x + 4 = 1, not zero; the equation fails.
- c +3/2: For x = 3/2, 2x + 4 = 7, not zero, so this option does not answer the question.
- d 2: For x = 2, 2x + 4 = 8, not zero; the right x is −2.
Your account is open, so all 30,000+ MCQs from every chapter are yours. Start practising SSC Higher Mathematics →
Want to keep going?
A free account carries you on to the next questions and opens 30,000+ MCQs from every chapter. Join before launch and Chirkut bundles are 60% off.
The ones you missed, worth one more look