Fundamentals of Math

Fundamentals of Mathematics

Chapter 3: Beginning Algebra Our world is full of numbers from clocks, to temperatures, sports odds, and stock figures. Well, Algebra is all about determining unknown quantities of numbers. You might know you can throw a ball at 40 mph, but do you know how far that ball will travel at that rate? Or if a home improvement project calls for 35 linear yards of lumber and you can only purchase increments in 2 × 4 then how many pieces do you need? With algebra, you can answer all of these questions, using what you know about numbers already to solve for the unknown. Let's start with a quick review of exponents and square roots (or cube roots) first though before we dive in. 3.1 Exponents Formally speaking, an exponent is defined as the quantity representing the power to which a given number or expression is to be raised, usually expressed as a raised symbol beside the number or expression (e.g., the 3 in 5 3 or 5^3). The symbol "^" is referred to as the carrot key and often the icon used on a calculator to indicate the following number is an exponent. In layman's terms though an exponent is just shorthand for repeated multiplication. For example, rather than write something like 2 × 2 × 2 × 2 × 2 × 2 × 2 we would write 2 7 instead. The larger number of the exponent is known as the base, and the exponent is the smaller number (visually smaller not necessarily size wise) written as a superscript.

Where and are integers and is the base and is the exponent.

Properties of Exponents Negatives and Exponents

Negative Base

Exponents only apply to the immediate base. If a negative sign is written in front of the base, it is only included in the repeated multiplication if and only if the entire base (number and sign) is included inside a parenthesis. Raising a number to a negative power is the same as taking 1 over the number raised to the positive power.

−5 4 = −1 × 5 × 5 × 5 = −625

Case #2

(−5) 4 = (−5) × (−5) × (−5) × (−5) = 625

Case #1

Negative Exponents

1 4 2

1 4 × 4

1 16

4 −2 =

=

=

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