Question 1 - A-Level Maths

Given that $$2 \ln ( 3 - x ) - \ln ( 21 - 2 x ) = 0$$ show that $$x ^ { 2 } - 4 x - 12 = 0$$ [4]
1. Write down the roots of the equation $x ^ { 2 } - 4 x - 12 = 0$.
2. State which of these two roots is not a solution of $$2 \ln ( 3 - x ) - \ln ( 21 - 2 x ) = 0$$ giving a reason for your answer.