.
The answer to the inequality log(x^2-7x) < log(3-x) + log2 is
~~~~~~~~~~~~~~~
//////////////////
How you do formulate the problem is similar to if somebody scratches the glass with a nail.
The normal mathematical formulation is THIS :
Solve logarithmic inequality log(x^2-7x) < log(3-x) + log(2).
See the solution below.
//////////////////
First, the domain for this inequality is the set of real numbers x such that
x^2 -7x > 0 and 3-x > 0,
or { x < 0 & x < 3 } U {x > 7 & x < 3 }.
Of the last two sets under the union sign, the second set {x > 7 & x < 3 } is empty;
so, the domain is the set { x < 0 }. (1)
Next, the given inequality is equivalent to
log(x^2 -7x) < log (2(3-x))
which implies (due to the monotonicy of the logarithm function)
x^2 - 7x < 6 - 2x.
What follows, is the solution procedure for this inequality.
x^2 - 5x - 6 < 0,
(x-6)*(x+1) < 0.
The last inequality has the solution set { -1 < x < 6 }. (2)
To get the final answer, we shoud take the intersection of the set (2) with the domain set (1).
The intersection is the set { -1 < x < 0 }, or, in the interval form, (-1,0).
ANSWER. The solution to given inequality is the set { -1 < x < 0 }, or, in the interval form, (-1,0).
Solved, answered, and explained.
I checked my solution visually, using online plotting calculator www.desmos.com.