Equations and Expressions

Objective edit

In this lesson, we will cover variables, expressions, equations, and methods of manipulating them.

Methods of manipulation include simplifying, substituting, and solving.

Key Terminology edit

Caption text
Term Definition Part of Speech
Variable A symbol used to represent a quantity that can change. Variables are numbers. Noun
Expression A representation of a quantity that uses numbers or variables, or the mathematical product of both. Noun
Equation A statement of equality using the symbol  . The quantities on each side of the equal sign are the same a each other. Noun
Solution A value or values that make equations true. Noun
Manipulate Modify an expression or an equation in a way that changes what's written on the page. Verb
Solve Look for solutions Verb
Simplify Rewrite an expression as a less complicated expression Verb
Substitute Replace a value with another thing of equal value Verb

Variables and Expressions edit

Equations edit

A simple equation:

2a+3b+c = 0

This equation has 3 variables (a,b and c);; 3 terms (2a, 3b and c);; and this equation is an equality, because here is an equal sign (=) between both sides of the equation.

Next: solution to a simple algebra problem. Solve the following equation for (a):


- -- - - - - - - - - Some trig stuff:

sin ɵ = Opposite-Side/Hypotenuse

cos ɵ = Adjacent-Side/Hypotenuse


See Also edit