If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

Using the quadratic formula

Sal solves the equation -7q^2+2q+9=0 by using the quadratic formula. Created by Sal Khan and Monterey Institute for Technology and Education.

Video transcript