Move all terms to the left side of the equation and simplify.
−2x2−8x+5=0-2x2-8x+5=0
The discriminant of a quadratic is the expression inside the radical of the quadratic formula.
b2−4(ac)b2-4ac
Substitute in the values of aa, bb, and cc.
(−8)2−4(−2⋅5)-82-4-2⋅5
Evaluate the result to find the discriminant.\
104