Math Problem Statement

Convert into logarithmic form 5^3 = 125, Determine the value of log sqrt{729}, and other logarithmic expressions as seen in the provided image.

Solution

Let's go through the questions in the image one by one and solve them:

a) Convert into logarithmic form 53=1255^3 = 125

In logarithmic form, ab=ca^b = c is written as logac=b\log_a{c} = b.

Thus: log5125=3\log_5{125} = 3

b) Determine the value of log729\log{\sqrt{729}}

First, simplify 729\sqrt{729}. Since 729=272729 = 27^2, 729=27\sqrt{729} = 27.

Now find log27\log{27}. Assuming it’s the common logarithm (base 10): log271.431\log{27} \approx 1.431

c) log1+2log2+3log2\log{1} + 2\log{2} + 3\log{\sqrt{2}}

We can simplify each term:

  1. log1=0\log{1} = 0 (since the logarithm of 1 in any base is 0).
  2. 2log2=log22=log42\log{2} = \log{2^2} = \log{4}.
  3. log2=12log2\log{\sqrt{2}} = \frac{1}{2}\log{2}, so 3log2=3×12log2=32log23\log{\sqrt{2}} = 3 \times \frac{1}{2} \log{2} = \frac{3}{2} \log{2}.

Thus: log1+2log2+3log2=log4+32log2\log{1} + 2\log{2} + 3\log{\sqrt{2}} = \log{4} + \frac{3}{2} \log{2}

d) log27+3log81\log{27} + 3\log{\sqrt{81}}

We simplify each term:

  1. log27=log33=3log3\log{27} = \log{3^3} = 3\log{3}.
  2. log81=log9\log{\sqrt{81}} = \log{9}, and 9=329 = 3^2, so log9=2log3\log{9} = 2\log{3}. Hence 3log81=3×2log3=6log33\log{\sqrt{81}} = 3 \times 2 \log{3} = 6\log{3}.

Thus: log27+3log81=3log3+6log3=9log3\log{27} + 3\log{\sqrt{81}} = 3\log{3} + 6\log{3} = 9\log{3}

e) log0.5+log18\log{0.5} + \log{18}

Using the logarithm product rule, loga+logb=log(a×b)\log{a} + \log{b} = \log{(a \times b)}:

log0.5+log18=log(0.5×18)=log9\log{0.5} + \log{18} = \log{(0.5 \times 18)} = \log{9}

f) log8+2log5log75+log18log8\log{\sqrt{8}} + 2\log{5} - \log{75} + \log{18} - \log{8}

We simplify using properties of logarithms:

  1. log8=12log8\log{\sqrt{8}} = \frac{1}{2} \log{8}.
  2. 2log5=log52=log252\log{5} = \log{5^2} = \log{25}.
  3. log75=log(3×25)=log3+log25\log{75} = \log{(3 \times 25)} = \log{3} + \log{25}.

Now combine terms using the product and quotient rules of logarithms.

g) log7=logxlogy\log{7} = \frac{\log{x}}{\log{y}}

This is simply a logarithmic equation where log7\log{7} is equal to the quotient of logx\log{x} and logy\log{y}. Without further context, we cannot solve for xx and yy.

h) log9log3\frac{\log{9}}{\log{3}}

Using logarithmic properties, log9=log32=2log3\log{9} = \log{3^2} = 2\log{3}. Hence:

log9log3=2log3log3=2\frac{\log{9}}{\log{3}} = \frac{2\log{3}}{\log{3}} = 2

i) log7×7log125\log{7} \times 7 \log{125}

We simplify log125=log53=3log5\log{125} = \log{5^3} = 3\log{5}, so:

7log125=7×3log5=21log57 \log{125} = 7 \times 3\log{5} = 21\log{5}

Thus the expression becomes log7×21log5\log{7} \times 21\log{5}.


Would you like more details or explanations on any of these steps?

Relative Questions:

  1. How are logarithmic properties applied to solve expressions involving multiple terms?
  2. Can you explain the relationship between logarithms and exponents?
  3. How do the rules for products and quotients in logarithms simplify complex expressions?
  4. Why is log1=0\log{1} = 0 for any base?
  5. What are the implications of changing the logarithmic base in calculations?

Tip:

Always remember to simplify radicals and exponents before applying logarithmic properties for easier calculations.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Logarithms
Exponents
Simplification of Expressions

Formulas

log_a{b} = c <=> a^c = b
log(a) + log(b) = log(ab)
log(a) - log(b) = log(a/b)
log(a^b) = b * log(a)
log(sqrt{a}) = (1/2) * log(a)

Theorems

Properties of Logarithms
Change of Base Theorem

Suitable Grade Level

Grades 10-12