.
Solve. Round to the nearest 100ths if necessary.
log6(x)+log6(x+5)=2
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
I interpret the given equation this way
+
= 2.
Using properties of logarithms, rewrite it this way
x*(x+5) =
,
x*(x+5) = 36,
x^2 + 5x - 36 = 0.
At this point, you can solve this quadratic equation using the quadratic formula.
Alternatively, you can solve it using factoring
(x+9)*(x-4) = 0,
x = -9 or x = 4.
The negative root does not work, since 'x' is under the logarithm, so we reject this root.
The other root, x = 4, works perfectly, as you can see when substituting it into the original equation.
Then the left side is
+
=
+
=
=
=
= 2,
the same as the right side.
ANSWER. The given equation has a unique solution x = 4.
Solved.