Resources:

http://tutorial.math.lamar.edu/

https://www.khanacademy.org/

https://www.brightstorm.com/math/precalculus/

http://www.coolmath.com/precalculus-review-calculus-intro

https://www.ixl.com/math/precalculus

http://www.wolframalpha.com/?scrlybrkr

https://www.youtube.com/