A quadratic equation with integral coefficients has integral roots.

A quadratic equation with rational coefficient cannot have irrational roots.

The quantity $b^2-4ac$ for a quadratic equation $a{x}^2+bx+c=0$ is called its discriminant.

$0.2$ is a root of the equation $x^2-0.4=0$.

The roots of the equation $a{x}^2+bx+c=0$ are always equal but opposite in sign when $b=0$.

The roots of the equation $\frac{1}{x-2}+\frac{1}{x-3}=7; \left(x\ne 2, 3\right)$ are equal.

$b^2-4ac$ in the quadratic equation $a{x}^2+bx+c=0$ is called the _____.