Tolong dong kak pake cara jalan nya ya kak
Matematika
agnesiaaa16
Pertanyaan
Tolong dong kak pake cara jalan nya ya kak
1 Jawaban
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1. Jawaban whongaliem
[tex]5) ^{6} log 45 = \frac{log 45}{log 6} [/tex]
[tex]= \frac{log (3^{2} . 5)}{log (2 . 3)} [/tex]
[tex]= \frac{log 3^{2} + log 5}{log 2 + log 3} [/tex]
[tex]= \frac{2 .log 3 + log 5}{log 2 + log 3} [/tex] ... beri bil pokok 3
[tex]= \frac{2 .^{3} log 3 + ^{3}log 5 }{ ^{3}log 2 + ^{3} log 3 } [/tex]
[tex]= \frac{2 . 1 + b}{ \frac{1}{a} + 1} [/tex] .... kalikan dengan a
[tex]= \frac{2a + ab}{1 + a} [/tex]
[tex]= \frac{ab + 2a}{a + 1} ..... jawaban : B[/tex]
6) 2x² + 10x + 5 = 0 ⇒ a = 2 ; b = 10 ; c = 5
[tex] \frac{ x_{1} }{ x_{2} } + \frac{ x_{2} }{ x_{1} } = \frac{ x_{1} ^{2} + x_{2} ^{2} }{ x_{1} . x_{2} } [/tex]
[tex]= \frac{ ( x_{1} + x_{2}) ^{2} - 2. x_{1} . x_{2} }{ x_{1} . x_{2} } [/tex]
[tex]= \frac{( -\frac{b}{a} )^{2} - 2 . (\frac{c}{a} )}{ \frac{c}{a} } [/tex]
[tex]= \frac{ ( -\frac{10}{2}) ^{2} - 2 . (\frac{5}{2} )}{ \frac{5}{2} } [/tex]
[tex]= \frac{25 - 5}{ \frac{5}{2} } [/tex]
[tex]= 20 . (\frac{2}{5} )[/tex]
= 8 ..... jawaban : B