Simplify the following expression and find the value of x:

2025

Simplify the following expression and find the value of x:

image.png

  1. A.

    0

  2. B.

    2

  3. C.

    4

  4. D.

    6

Attempted by 3 students.

Show answer & explanation

Correct answer: C

Step-by-Step Solution

To find the value of x, we need to simplify the given exponential expressions by expressing both sides with the same base.

  1. Simplify the equations:

    • Given equation 1: 3^(x - y) = 27

      • We know that 27 = 3^3.

      • Therefore: 3^(x - y) = 3^3

      • Equating the exponents: x - y = 3 --- (Equation 1)

    • Given equation 2: 3^(x + y) = 243

      • We know that 243 = 3^5.

      • Therefore: 3^(x + y) = 3^5

      • Equating the exponents: x + y = 5 --- (Equation 2)

  2. Solve the system of linear equations:

    • Now we have a simple system of two linear equations:

      1. x - y = 3

      2. x + y = 5

    • Add the two equations together: (x - y) + (x + y) = 3 + 5 2x = 8

    • Solve for x: x = 4

Explore the full course: Amcat Preparation