2x^2 - 5x - 10 = 0 (Use " ^ " to denote exponentiation, please.)
a = 2; b = -5; c = -10, and so the discriminant, b^2-4ac, is 25-4(2)(-10) = 105.
The roots are:
-(-5) plus or minus √105 5 plus or minus √105
x = -------------------------------------- = -----------------------------------
4 4
