Dude, you're awesome! Yeah, it was my mistake, correct answer is C! I see what you did, you did it much easier than the mgmat website.
When simplifying the equation like 4/X + 3X= 3X-36, to remove the denominator, we multiply with 3X,by both sides, is this correct? And this gives us 4+3x^2=3x^2-36 (are you multiplying by X on the left side to both sides? to square both 3X's?, I'm assuming this isolates the problem to 4=-36? then you divide by 4.
I don't follow why this becomes
How about instead of multiplying the equation by 'x', why not subtract '3x' from both sides first => 4/x = -36
Then multiply both sides by 'x' => 4 = -36x
Divide both sides by '-36' and simplify