# How do you find value of discriminant then describe number and type of solutions for #x^2 - 21 = 4x#?

##### 1 Answer

Feb 22, 2016

First rearrange the equation into standard form,

#### Explanation:

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.