
Log3(x-5)=log3(x+9) log3(5x-3)=3 lg(x^2-x)=1-lg5 log2 x=1+log2 5 log5(x+1) + log5 (x-1) =3log5 2


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To solve these logarithmic equations, we'll handle each one separately:
- Log3(x-5) = log3(x+9)
Since the bases are the same (logarithms are base 3), you can set the arguments equal to each other:
x - 5 = x + 9
Now, isolate x:
x - x = 9 + 5 0 = 14
This equation has no solution, which means there are no real values of x that satisfy the original equation.
- Log3(5x-3) = 3
Again, since the bases are the same, set the arguments equal to each other:
5x - 3 = 3
Now, isolate x:
5x = 3 + 3 5x = 6
Divide by 5:
x = 6/5
- lg(x^2-x) = 1 - lg(5)
First, let's clarify what "lg" means. It's often used to denote the base-10 logarithm, which is more commonly written as "log10." Assuming that, we can rewrite the equation as:
log10(x^2-x) = 1 - log10(5)
Now, let's use properties of logarithms to simplify this equation. Remember that subtracting logarithms is equivalent to dividing their arguments:
log10(x^2-x) = log10(10) - log10(5)
log10(x^2-x) = log10(2)
Now, set the arguments equal to each other:
x^2 - x = 2
Rearrange and solve for x:
x^2 - x - 2 = 0
Factor the quadratic:
(x - 2)(x + 1) = 0
Now, set each factor equal to zero and solve for x:
x - 2 = 0 --> x = 2 x + 1 = 0 --> x = -1
So, there are two solutions: x = 2 and x = -1.
- log2(x) = 1 + log2(5)
First, subtract log2(5) from both sides:
log2(x) - log2(5) = 1
Now, use the properties of logarithms to combine the logarithms on the left side:
log2(x/5) = 1
Now, rewrite this equation in exponential form:
x/5 = 2^1
x/5 = 2
Now, multiply both sides by 5 to solve for x:
x = 5 * 2
x = 10
- log5(x+1) + log5(x-1) = 3 * log5(2)
Apply the logarithmic properties:
log5((x+1)(x-1)) = log5(2^3)
Now, simplify the right side:
log5((x+1)(x-1)) = log5(8)
Set the arguments equal to each other:
(x+1)(x-1) = 8
Now, expand the left side:
x^2 - 1 = 8
Add 1 to both sides:
x^2 = 9
Take the square root of both sides (remembering both positive and negative roots):
x = ±3
So, there are two solutions: x = 3 and x = -3.
To summarize, the solutions to the given equations are as follows:
- No real solutions.
- x = 6/5
- x = 2 and x = -1
- x = 10
- x = 3 and x = -3


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