We'll impose the constraints of existence of
logarithms:
2x+ 2
>0
2x>-2
x>-1
3x>0
x>0
The
interval of admissible solutions for the given equation is: (0 ;
+infinite).
Now, we'll sove the equation, adding log 3x
both sides:
log (2x+2) + log 3x =
1
We'll apply the product
rule:
log [6x(x+1)] = 1
We'll
take antilogarithm:
6x(x+1) =
10
We'll remove the
brackets:
6x^2 + 6x - 10 =
0
We'll divide by 2:
3x^2 + 3x
- 5 = 0
We'll apply the quadratic
formula:
x1 = [-3+sqrt(9 +
60)]/6
x1 = [-3+sqrt(69)]/6
x2
= [-3-sqrt(69)]/6
Since the 2nd value is negative, it
doesn't belong to the range of admissible values, so we'll reject
it.
The only valid solution of the equation
is:
x1 =
[-3+sqrt(69)]/6
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