First, use distributive property on the right half.
2 * 5 = 10
2 * 2n = 4n
4n - 9 = 10 + 4n
Add 9 to both sides
4n = 19 + 4n
Subtract 4n from both sides
0 = 19
But thats not true. Therefore, there is no solution.
The answer to this is 7.5.
The right answer is not among those offered. The domain is
.. {-9, -6, 4, 7}
___
The 4th selection {4, 7} is the best of those offered, but it is not correct.
The answer is -16 and -5.