This does not give real roots. Using the quadratic formula, -b plus or minus root of (b^2 - 4* a * c) all over 2a , this gives the square root of a negative which gives no real solutions.
However if this is correct and you are not looking for real sollutions, it goes to...
(10(+/-) sqrt(25-360) ) / 2
= 5 (+/-) (sqrt-335) /2 = 5 (+/-) sqrt(335) i /2
aprox = 5+9.2i, 5-9.2i then sub these in for y to get coordinates
This is most likely not what your looking for however and have probably coppied the question down wrong.