Polynomial Equations Courses
École normale supérieure via Coursera Pre-Calculus: Functions
University of California, Irvine via Coursera Advanced Functions: A Complete Course on Precalculus
Udemy A-level Further Mathematics for Year 12 - Course 1: Complex Numbers, Matrices, Roots of Polynomial Equations and Vectors
Imperial College London via edX Functions
Jeremy Klassen via YouTube Algebra 2
YouTube Algebra 2 Course - Unit 4
YouTube GRE Math: Study Guide & Test Prep
Study.com CSET Math Subtest 1 (211) Study Guide & Practice Test
Study.com Why Don't They Teach This Simple Visual Solution - Lill's Method
Mathologer via YouTube