Khan Academy: Algebra Basics
Khan Academy

Course summary. Foundations. Algebraic expressions. Linear equations and inequalities. Graphing lines and slope. Systems of equations. Expressions with exponents. Quadratics and polynomials.

Khan Academy: Algebra 1
Khan Academy

TheĀ Algebra 1 course, often taught in the 9th grade, covers Linear equations, inequalities, functions, and graphs, Systems of equations and inequalities, and more.