The question is: determine the value(s) of m in each equation so that the two roots are equal. My teacher told me to use a discriminant. What's that?

$\displaystyle x^2-6x+m=o$

$\displaystyle 4x^2+mx+25$

Determine the value(s) of n in each equation such that one root is triple the other root.

$\displaystyle 3x^2-4x+n=0$

$\displaystyle 4x^2+nx+27=0$

Help would be GREATLY appreaciated!!!

Thank you!