The standard form of a quadratic equation is Ax^2 + Bx + C = 0. So for –6 = x^2 + 4x – 1 to be in its standard form, we can move -6 to the other side of the equation and have x^2 + 4x + (-1 +6) = 0 x^2 + 4x + 5 = 0 So, from the standard form, the value of of C is 5.