You can put this solution on YOUR website!
Remeber the "zero product" rule?
Your work so far is immpecable. When you get to the line:
Apply the zero product rule:
Clearly not true.
You can ignore the 4 as it is not pertinent to the x-intercepts.
Another way to look at doing this problem (if the 4 still bothers you) is:
Divide both sides by -4.
Apply the zero product rule.
and these are the x-intercepts.