Solve the logarithmic equation for x, as in Example 7. (Enter your answers as a comma-separated list.)
2 log(x) = log(2) + log(4x − 6)
Solve for x:
(2 log(x))/log(10) = log(4 x - 6)/log(10) + log(2)/log(10)
Subtract log(4 x - 6)/log(10) + log(2)/log(10) from both sides:
-log(2)/log(10) + (2 log(x))/log(10) - log(4 x - 6)/log(10) = 0
Bring -log(2)/log(10) + (2 log(x))/log(10) - log(4 x - 6)/log(10) together using the common denominator log(10):
-(log(2) - 2 log(x) + log(4 x - 6))/log(10) = 0
Multiply both sides by -log(10):
log(2) - 2 log(x) + log(4 x - 6) = 0
log(2) - 2 log(x) + log(4 x - 6) = log(2) + log(1/x^2) + log(4 x - 6) = log((2 (4 x - 6))/x^2):
log((2 (4 x - 6))/x^2) = 0
Cancel logarithms by taking exp of both sides:
(2 (4 x - 6))/x^2 = 1
Multiply both sides by x^2:
2 (4 x - 6) = x^2
Expand out terms of the left hand side:
8 x - 12 = x^2
Subtract x^2 from both sides:
-x^2 + 8 x - 12 = 0
The left hand side factors into a product with three terms:
-(x - 6) (x - 2) = 0
Multiply both sides by -1:
(x - 6) (x - 2) = 0
Split into two equations:
x - 6 = 0 or x - 2 = 0
Add 6 to both sides:
x = 6 or x - 2 = 0
Add 2 to both sides:
x = 6 or x = 2