Equations and Expressions
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
|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
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