Respuesta :
Answer:
Error:[tex]lnx^2=ln 3x[/tex] not [tex]ln\frac{3x}{0}[/tex]
Solution:x=0 and 3
Step-by-step explanation:
We have to find the error and correct answer
Given:[tex]2ln x=ln(3x)-[ln9-2ln(3)][/tex]
[tex]lnx^2=ln(3x)-[ln9-ln3^2][/tex]
Using the formula
[tex]alog b=logb^a[/tex]
[tex]lnx^2=ln(3x)-[ln9-ln9][/tex]
[tex]lnx^2=ln(3x)-0[/tex]
[tex]lnx^2=ln(3x)[/tex]
[tex]x^2=3x[/tex]
[tex]x^2-3x=0[/tex]
[tex]x(x-3)=0[/tex]
Therefore, x=0 and x=3
But last step in the given solution
[tex]lnx^2=ln\frac{3x}{0}=\infty[/tex]
It is wrong this property is used when
[tex]log m-log n[/tex] then
[tex]log\frac{m}{n}[/tex]
Hence, the student wrote [tex]lnx^2=ln\frac{3x}{0}[/tex]instead of [tex]lnx^2=ln3x[/tex] and solution is given by
x=0 and x=3
Answer:
Since 0 in ln(3x) - 0 is not a logarithm, the property of logarithms cannot be used here.
The difference shown cannot be written as a quotient of logarithms.
The step ln(x2) = ln(3x) - (0) reduces to
ln(x2) = ln(3x).
The possible solutions are 0 and 3, with 0 being extraneous.
right on edge