solve each equation by factoring and using the zero product property
1/12x^2 - 2/3x = 4
( the x^2 and x are in the middle between the numbers. It is not 12x^2 or 3x )
so we're talking
$$\frac{1}{12}x^2-\frac{2}{3}x=4$$
start by multiplying both sides by 12 and getting all the terms on the left side and 0 on the right side.
Then factor that quadratic polynomial on the left via one of the methods you've learned. Here if you need a review.
Then just apply the zero product property to your two factors to obtain your two solutions.