Solve the logarithmic equation 2 ( lo g 3 x − 1 ) = lo g 3 x for x , which gives x = 9 .
Substitute the value of x into the equation y = x + 1 .
Calculate y = 9 + 1 = 3 + 1 = 4 .
The final answer is 4 .
Explanation
Problem Analysis We are given two equations:
2 ( lo g 3 x − 1 ) = lo g 3 x
y = x + 1
Our goal is to find the value of y . To do this, we first need to solve the first equation for x , and then substitute that value into the second equation to find y .
Solving for x Let's solve the first equation for x :
2 ( lo g 3 x − 1 ) = lo g 3 x
Distribute the 2:
2 lo g 3 x − 2 = lo g 3 x
Subtract lo g 3 x from both sides:
2 lo g 3 x − lo g 3 x = 2
lo g 3 x = 2
Now, rewrite the equation in exponential form:
x = 3 2
x = 9
Solving for y Now that we have the value of x , we can substitute it into the second equation to find y :
y = x + 1
Substitute x = 9 :
y = 9 + 1
y = 3 + 1
y = 4
Final Answer Therefore, the value of y is 4.
Examples
Imagine you are designing a staircase where the height of each step ( y ) depends on the length of the base of the step ( x ) following the equation y = x + 1 . If you also know that the length x is related to a logarithmic equation 2 ( lo g 3 x − 1 ) = lo g 3 x , solving these equations simultaneously helps you determine the exact height of each step. This ensures that the staircase is both aesthetically pleasing and ergonomically sound, providing a comfortable and safe ascent.
We solved the logarithmic equation 2 ( lo g 3 x − 1 ) = lo g 3 x to find that x = 9 . Then, substituting this value into the equation y = x + 1 gives us y = 4 .
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