• ### Unit 3: Algebra

This unit explores several essential algebra skills: working with algebraic expressions, solving linear and quadratic equations, and representing them on the coordinate plane. You will also learn how to apply algebraic expressions, equations, and graphs to describe and analyze word problems.

Completing this unit should take you approximately 26 hours.

• ### 3.1: Algebraic Expressions

This section reviews basic algebra skills: working with variables, simplifying variable (algebraic) expressions, and translating verbal expressions into mathematics.

• ### 3.2: Linear Equations with One Variable

In this section, you will learn how to solve general linear equations with one variable and use the equations to describe common situations in word problems.

• ### 3.3: Linear Inequalities with One Variable

Solving inequalities is very similar to solving equations, with a few important distinctions. First, the solution to an inequality is a set of numbers rather than just one value. This is why the solutions of inequalities are typically represented on a number line. And, while you can still do the same thing to both sides of inequality to isolate the variable, you have to remember to flip the sign of inequality (less to greater, and vice versa) when multiplying and dividing by a negative number.

Quadratic equations are equations that contain a variable in the second power (squared). This section introduces the primary method for solving quadratic equations: quadratic formula. Quadratic equations can have two real solutions (rational or irrational), one real rational solution, or no real solutions.

• ### 3.5: Graphs of Linear Equations

This section explores how linear equations can be represented by graphs on the coordinate plane and the properties of these graphs.

• ### 3.6: Graphs of Quadratic Equations

This section explores how quadratic equations can be represented by graphs on the coordinate plane and the properties of these graphs.

• ### 3.7: Functions

This section will introduce the concepts of relations and functions.