Questions: You are only allowed to use integer exponents.
- Use sqrt(...) to deal with fractional exponents.
- Make sure your final answer is written as a single logarithm.
a. 7 log (x)+5 log (z)-1/2 log (y)=log ((x^7 z^5)/sqrt(y))
b. 1/2 log (x)-5 log (y)-7 log (z)=log (sqrt(x)/(y^5 z^7))
c. 5/2 log (x)-7/2 log (y)-5/2 log (z)=log (sqrt(x^5)/(y sqrt(7/2) sqrt(z^5)))
Hint
- Do you have a sum of logarithms? Use the fact that log (a)+log (b)=log (a b).
- Do you have a difference of logarithms? Use the fact that log (a)-log (b)=log (a/b).
- Remember that a^(m/n)=sqrt[n](a^m).
Transcript text: - You are only allowed to use integer exponents.
- Use sqrt(...) to deal with fractional exponents.
- Make sure your final answer is written as a single logarithm.
a. $7 \log (x)+5 \log (z)-\frac{1}{2} \log (y)=\log \left(\frac{x^{7} z^{5}}{\sqrt{y}}\right)$
b. $\frac{1}{2} \log (x)-5 \log (y)-7 \log (z)=\log \left(\frac{\sqrt{x}}{y^{5} z^{7}}\right)$
$\checkmark$
c. $\frac{5}{2} \log (x)-\frac{7}{2} \log (y)-\frac{5}{2} \log (z)=\log \left(\frac{\sqrt{x^{5}}}{y \sqrt{\frac{7}{2}} \sqrt{z^{5}}}\right)$
Hint
- Do you have a sum of logarithms? Use the fact that ${ }^{\prime} \log (\operatorname{color}\{$ red $\{$ a $\})+\log (\operatorname{color}\{b l u e\}(b\})=\log (\operatorname{color}\{$ red $\{$ a $\} \operatorname{color}\{$ blue $\}$ (b)).
- Do you have a difference of logarithms? Use the fact that ${ }^{\prime} \log ($ color\{red $\{$ a $\})-\log (\operatorname{color}\{$ blue $\}$ b $\left.\}\right)=\log (f r a c\{(\operatorname{color}\{(r e d\}$ a $\}\}$ \{color\{blue\}(b]\}).
- Remember that $a^{\frac{m}{n}}=\sqrt[n]{a^{m}}$.
Solution
Solution Steps
To solve these logarithmic expressions, we will use the properties of logarithms to combine them into a single logarithm. Specifically, we will use the properties:
We start with the expression \(7 \log(x) + 5 \log(z) - \frac{1}{2} \log(y)\). Using the properties of logarithms, we can combine these terms into a single logarithm:
\[7 \log(x) + 5 \log(z) - \frac{1}{2} \log(y) = \log(x^7) + \log(z^5) - \log(y^{1/2})\]
\[= \log(x^7 z^5) - \log(y^{1/2})\]
\[= \log\left(\frac{x^7 z^5}{y^{1/2}}\right)\]
\[= \log\left(\frac{x^7 z^5}{\sqrt{y}}\right)\]
Part (b)
We start with the expression \(\frac{1}{2} \log(x) - 5 \log(y) - 7 \log(z)\). Using the properties of logarithms, we can combine these terms into a single logarithm:
\[\frac{1}{2} \log(x) - 5 \log(y) - 7 \log(z) = \log(x^{1/2}) - \log(y^5) - \log(z^7)\]
\[= \log\left(\frac{x^{1/2}}{y^5}\right) - \log(z^7)\]
\[= \log\left(\frac{x^{1/2}}{y^5 z^7}\right)\]
\[= \log\left(\frac{\sqrt{x}}{y^5 z^7}\right)\]
Part (c)
We start with the expression \(\frac{5}{2} \log(x) - \frac{7}{2} \log(y) - \frac{5}{2} \log(z)\). Using the properties of logarithms, we can combine these terms into a single logarithm:
\[\frac{5}{2} \log(x) - \frac{7}{2} \log(y) - \frac{5}{2} \log(z) = \log(x^{5/2}) - \log(y^{7/2}) - \log(z^{5/2})\]
\[= \log\left(\frac{x^{5/2}}{y^{7/2}}\right) - \log(z^{5/2})\]
\[= \log\left(\frac{x^{5/2}}{y^{7/2} z^{5/2}}\right)\]
\[= \log\left(\frac{\sqrt{x^5}}{y^{7/2} \sqrt{z^5}}\right)\]
Step 1: Solve Part (a)
We start with the expression:
\[
7 \log(x) + 5 \log(z) - \frac{1}{2} \log(y)
\]
Using the properties of logarithms, we combine the terms:
\[
= \log(x^7) + \log(z^5) - \log(y^{1/2}) = \log\left(\frac{x^7 z^5}{\sqrt{y}}\right)
\]
Substituting \(x = 2\), \(y = 3\), and \(z = 4\):
\[
= \log\left(\frac{2^7 \cdot 4^5}{\sqrt{3}}\right) \approx 4.8789
\]
Step 2: Solve Part (b)
We start with the expression:
\[
\frac{1}{2} \log(x) - 5 \log(y) - 7 \log(z)
\]
Using the properties of logarithms, we combine the terms:
\[
= \log(x^{1/2}) - \log(y^5) - \log(z^7) = \log\left(\frac{x^{1/2}}{y^5 z^7}\right)
\]
Substituting \(x = 2\), \(y = 3\), and \(z = 4\):
\[
= \log\left(\frac{\sqrt{2}}{3^5 \cdot 4^7}\right) \approx -6.4495
\]
Step 3: Solve Part (c)
We start with the expression:
\[
\frac{5}{2} \log(x) - \frac{7}{2} \log(y) - \frac{5}{2} \log(z)
\]
Using the properties of logarithms, we combine the terms:
\[
= \log(x^{5/2}) - \log(y^{7/2}) - \log(z^{5/2}) = \log\left(\frac{x^{5/2}}{y^{7/2} z^{5/2}}\right)
\]
Substituting \(x = 2\), \(y = 3\), and \(z = 4\):
\[
= \log\left(\frac{\sqrt{x^5}}{y^{7/2} \sqrt{z^5}}\right) \approx -2.4225
\]
Final Answer
The results for each part are:
Part (a): \(\approx 4.8789\)
Part (b): \(\approx -6.4495\)
Part (c): \(\approx -2.4225\)
Thus, the final answers are:
\[
\boxed{4.8789}, \quad \boxed{-6.4495}, \quad \boxed{-2.4225}
\]