How do you find value of discriminant then describe number and type of solutions for #x^2 - 21 = 4x#?
First rearrange the equation into standard form,
Standard form for a quadratic equation is
Once the equation has been arranged in this form, the discriminant is given by
If the discriminant is positive there are two real roots, if it is negative there are two imaginary roots, if it is zero there is one real root.