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MATH HELP!!! 100PTS!!!

Suppose that u=log10(3) and v=log10(5). Find possible formulas for the following expressions in terms of u and/or v. Your answers should NOT involve any log 's.

a) log10(0.6)=
u-v


b) log10(0.25)=



c) log10(27000)=
3+3u


d) log10(sqrt10)=

Respuesta :

Answer:

a)  u - v

b)  2v - 2

c)  3u + 3

d)  ¹/₂

Step-by-step explanation:

Given:

 [tex]u=\log_{10}3[/tex]

 [tex]v=\log_{10}5[/tex]

Part (a)

Rewrite 0.6 as a fraction:

[tex]\implies \log_{10}(0.6)=\log_{10}\left(\dfrac{3}{5}\right)[/tex]

[tex]\textsf{Apply the quotient log law}: \quad \log_a\frac{x}{y}=\log_ax - \log_ay:[/tex]

[tex]\implies \log_{10}\left(\dfrac{3}{5}\right)=\log_{10}3-\log_{10}5[/tex]

Substitute the values of u and v:

[tex]\implies \log_{10}3-\log_{10}5=u-v[/tex]

Part (b)

Rewrite 0.25 as 25/100:

[tex]\implies \log_{10}(0.25)=\log_{10}\left(\dfrac{25}{100}\right)[/tex]

[tex]\textsf{Apply the quotient log law}: \quad \log_a\frac{x}{y}=\log_ax - \log_ay[/tex]

[tex]\implies \log_{10}\left(\dfrac{25}{100}\right)=\log_{10}(25)-\log_{10}(100)[/tex]

Rewrite 25 as 5² and 100 as 10²:

[tex]\implies \log_{10}(25)-\log_{10}(100)=\log_{10}(5^2)-\log_{10}(10^2)[/tex]

[tex]\textsf{Appy the Power log law}: \quad \log_ax^n=n\log_ax[/tex]

[tex]\implies \log_{10}(5^2)-\log_{10}(10^2)=2\log_{10}5-2\log_{10}10[/tex]

[tex]\textsf{Apply the log law}: \quad \log_aa=1[/tex]

[tex]\implies 2\log_{10}5-2\log_{10}10=2\log_{10}5-2(1)[/tex]

Substitute the value of v:

[tex]\implies 2\log_{10}5-2(1)=2v-2[/tex]

Part (c)

Rewrite 27000 as 30³:

[tex]\implies \log_{10}(27000)=\log_{10}(30^3)[/tex]

[tex]\textsf{Appy the Power log law}: \quad \log_ax^n=n\log_ax[/tex]

[tex]\implies \log_{10}(30^3)=3\log_{10}(30)[/tex]

[tex]\textsf{Apply the log product law}: \quad \log_axy=\log_ax + \log_ay[/tex]

[tex]\implies 3\log_{10}(30)=3\log_{10}(3)+3\log_{10}(10)[/tex]

[tex]\textsf{Apply the log law}: \quad \log_aa=1[/tex]

[tex]\implies 3\log_{10}(3)+3\log_{10}(10)=3\log_{10}(3)+3(1)[/tex]

Substitute the value of u:

[tex]\implies 3\log_{10}(3)+3(1)=3u+3[/tex]

Part (d)

Rewrite √10 as [tex]10^{\frac{1}{2}}[/tex] :

[tex]\implies \log_{10}(\sqrt{10})=\log_{10}(10^{\frac{1}{2}})[/tex]

[tex]\textsf{Appy the Power log law}: \quad \log_ax^n=n\log_ax[/tex]

[tex]\implies \log_{10}(10^{\frac{1}{2}})=\dfrac{1}{2}\log_{10}(10)[/tex]

[tex]\textsf{Apply the log law}: \quad \log_aa=1[/tex]

[tex]\implies \dfrac{1}{2}\log_{10}(10)=\dfrac{1}{2}(1)=\dfrac{1}{2}[/tex]