Answer:
Step-by-step explanation:
hm. this may not be helpful if you have to take that specific route in order to get the answer, but this would be the perfect candate for the quadratic formula. -b+/- Sqrt(b^2-4ac) all over 2a. that would give you -4+/ sqrt(7), and this may be the starting point you need to get everyhitng to make sense. Im sorry I cant help more
Best of luck!
