Math Problem Statement

Solve the logarithmic equations shown in the provided image.

Solution

Let's analyze and solve the logarithmic equations shown in the image:

Equation (a):

log5(2x)=3\log_5(2x) = 3

  1. Rewrite the logarithmic equation in exponential form: 2x=532x = 5^3 2x=1252x = 125
  2. Solve for xx: x=1252=62.5x = \frac{125}{2} = 62.5

Solution: x=62.5x = 62.5


Equation (b):

log5(x+1)=1\log_5(x+1) = -1

  1. Rewrite the logarithmic equation in exponential form: x+1=51x+1 = 5^{-1} x+1=15x+1 = \frac{1}{5}
  2. Solve for xx: x=151=45x = \frac{1}{5} - 1 = \frac{-4}{5}

Solution: x=45x = -\frac{4}{5}


Equation (c):

log(4)log(x)=2\log(4) - \log(x) = 2

  1. Use the logarithmic property log(a)log(b)=log(ab)\log(a) - \log(b) = \log\left(\frac{a}{b}\right): log(4x)=2\log\left(\frac{4}{x}\right) = 2
  2. Rewrite the logarithmic equation in exponential form: 4x=102\frac{4}{x} = 10^2 4x=100\frac{4}{x} = 100
  3. Solve for xx: x=4100=0.04x = \frac{4}{100} = 0.04

Solution: x=0.04x = 0.04


Equation (d):

2log3(6)+log3(y)=42\log_3(6) + \log_3(y) = 4

  1. Simplify 2log3(6)2\log_3(6) using the property alogb(c)=logb(ca)a\log_b(c) = \log_b(c^a): 2log3(6)=log3(62)=log3(36)2\log_3(6) = \log_3(6^2) = \log_3(36) So the equation becomes: log3(36)+log3(y)=4\log_3(36) + \log_3(y) = 4
  2. Use the logarithmic property logb(a)+logb(c)=logb(ac)\log_b(a) + \log_b(c) = \log_b(ac): log3(36y)=4\log_3(36y) = 4
  3. Rewrite the logarithmic equation in exponential form: 36y=3436y = 3^4 36y=8136y = 81
  4. Solve for yy: y=8136=94=2.25y = \frac{81}{36} = \frac{9}{4} = 2.25

Solution: y=2.25y = 2.25


Summary of Solutions:

(a) x=62.5x = 62.5
(b) x=45x = -\frac{4}{5}
(c) x=0.04x = 0.04
(d) y=2.25y = 2.25

Do you want any of these steps explained in more detail, or have any questions?


Related Questions:

  1. What are the basic properties of logarithms used to solve equations?
  2. How do you convert a logarithmic equation to its exponential form?
  3. Can you explain how to check if a logarithmic solution is valid (e.g., x>0x > 0)?
  4. How does the base of the logarithm affect the equation's solution?
  5. What happens if logarithmic equations have multiple logs on both sides?

Tip:

When solving logarithmic equations, always ensure the arguments of the logarithms are positive, as logarithms are undefined for non-positive values.

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Math Problem Analysis

Mathematical Concepts

Logarithmic Equations
Exponential Equations
Logarithmic Properties

Formulas

log_b(a) = c implies b^c = a
log_b(a) - log_b(c) = log_b(a/c)
a log_b(c) = log_b(c^a)

Theorems

Properties of Logarithms
Definition of Logarithms

Suitable Grade Level

Grades 9-11