Math Problem Statement

What is the general method for solving ax=bax=b?

Solution

To solve the general exponential equation ax=ba^x = b, where a>0a > 0 and a1a \neq 1, follow these steps:

1. Take the logarithm of both sides:

Apply the logarithm to both sides of the equation. You can use any logarithm, but it's common to use the natural logarithm (ln\ln) or the common logarithm (log\log). For this explanation, we'll use the natural logarithm.

ln(ax)=ln(b)\ln(a^x) = \ln(b)

2. Use the power rule of logarithms:

The power rule states that ln(ax)=xln(a)\ln(a^x) = x \cdot \ln(a). Apply this to the left side:

xln(a)=ln(b)x \cdot \ln(a) = \ln(b)

3. Solve for xx:

Now, isolate xx by dividing both sides by ln(a)\ln(a):

x=ln(b)ln(a)x = \frac{\ln(b)}{\ln(a)}

Example:

Let's say you have 3x=813^x = 81. To solve it:

  1. Take the logarithm of both sides:

    ln(3x)=ln(81)\ln(3^x) = \ln(81)

  2. Use the power rule:

    xln(3)=ln(81)x \cdot \ln(3) = \ln(81)

  3. Solve for xx:

    x=ln(81)ln(3)x = \frac{\ln(81)}{\ln(3)}

    Since 81=3481 = 3^4, x=4x = 4.

Would you like more details or have other questions?

Here are 8 related questions you might find useful:

  1. How can you solve 2x=502^x = 50 using logarithms?
  2. What is the difference between using natural logarithms and common logarithms in these equations?
  3. How would you solve 5x=1005^x = 100?
  4. Can you solve ax=ba^x = b if aa or bb is a negative number?
  5. What happens if a=1a = 1 in the equation ax=ba^x = b?
  6. How do you solve exponential equations with different bases, like 2x=3y2^x = 3^y?
  7. How would you solve an equation like 32x=813^{2x} = 81?
  8. What is the method for solving ex=7e^x = 7, where ee is the base of natural logarithms?

Tip: When solving exponential equations, always consider the properties of logarithms and how they can simplify the process.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Exponential Equations
Logarithms

Formulas

Exponential equation formula a^x = b
Logarithm power rule

Theorems

-

Suitable Grade Level

Grades 10-12