Respuesta :
Answer:
x = 1
x = -1
Step-by-step explanation:
Solve the equation
[tex]6^{\frac{2}{x}}+4^{\frac{1}{x}}=\dfrac{10}{3}\cdot 12^{\frac{1}{x}}[/tex]
First, note that
[tex]4^{\frac{1}{x}}=2^{\frac{2}{x}}[/tex]
Now, divide the whole equation by [tex]2^{\frac{2}{x}}[/tex]
[tex]\dfrac{6^{\frac{2}{x}}}{2^{\frac{2}{x}}}+\dfrac{2^{\frac{2}{x}}}{2^{\frac{2}{x}}}=\dfrac{10}{3}\cdot \dfrac{12^{\frac{1}{x}}}{2^{\frac{2}{x}}}[/tex]
[tex]3^{\frac{2}{x}}+1=\dfrac{10}{3}\cdot \dfrac{12^{\frac{1}{x}}}{4^{\frac{1}{x}}}\\ \\3^{\frac{2}{x}}+1=\dfrac{10}{3}\cdot 3^{\frac{1}{x}}[/tex]
Use substitution
[tex]t=3^{\frac{1}{x}}[/tex]
Then
[tex]t^2+1=\dfrac{10}{3}t[/tex]
Multiply by 3:
[tex]3t^2+3=10t\\ \\3t^2-10t+3=0\\ \\D=(-10)^2-4\cdot 3\cdot 3=100-36=64\\ \\t_{1,2}=\dfrac{-(-10)\pm \sqrt{64}}{2\cdot 3}=\dfrac{10\pm 8}{6}=3,\dfrac{1}{3}[/tex]
Thus,
[tex]3^{\frac{1}{x}}=3\Rightarrow \dfrac{1}{x}=1,\ x=1\\ \\3^{\frac{1}{x}}=\dfrac{1}{3}\Rightarrow \dfrac{1}{x}=-1,\ x=-1[/tex]