Variable $x$ cannot be equal to $0$ since division by zero is not defined. Multiply both sides of the equation by $12x$, the least common multiple of $3x,2x,12$.
$$4\times 2-6\times 3=x$$
Do the multiplications.
$$8-18=x$$
Subtract $18$ from $8$ to get $-10$.
$$-10=x$$
Swap sides so that all variable terms are on the left hand side.
