Exercise Zone : Pertidaksamaan Logaritma
Table of Contents
Tipe:
No.
7log x + 2 xlog 7 = 3ALTERNATIF PENYELESAIAN
Misal 7log x = p, maka xlog 7 = \(\dfrac1p\) .
\(\begin{aligned} p+\dfrac2p&=3&{\color{red}\times p}\\[3.7pt] p^2+2&=3p\\ p^2-3p+2&=0\\ (p-1)(p-2)&=0 \end{aligned}\)
p = 1, atau p = 2
\(\begin{aligned} p+\dfrac2p&=3&{\color{red}\times p}\\[3.7pt] p^2+2&=3p\\ p^2-3p+2&=0\\ (p-1)(p-2)&=0 \end{aligned}\)
p = 1, atau p = 2
- p = 1,
\(\begin{aligned} ^7\negmedspace\log x&=1\\ x&=7^1\\ &=\boxed{\boxed{7}} \end{aligned}\)
- p = 2,
\(\begin{aligned} ^7\negmedspace\log x&=2\\ x&=7^2\\ &=\boxed{\boxed{49}} \end{aligned}\)
Jadi, x = 7 atau x = 49.
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