What is the discriminant of the quadratic equation 2x + 5x2 = 1? –18

For this case we have the following equation:
 2x + 5x2 = 1
 Rewriting we have:
 5x2 + 2x - 1 = 0
 We have then:
 a = 5
 b = 2
 c = -1
 The discriminant is:
 b ^ 2 - 4 * a * c
 Substituting values we have:
 (2) ^ 2 - 4 * 5 * (- 1)
 4 + 20
 24
 
 The discriminant of the quadratic equation is:
 24