Algebra 1 Unit 1- Foundations for Algebra

variable

a letter or symbol used to represent a value that can change

constant

a value that does not change

numerical expression

a mathematical expression that may contain only constants and operations

algebraic expression

a mathematical expression that may contain variables, constants, and operations

evaluate

to find the value of an expression

absolute value

the distance a number is from zero on the number line

opposites

two numbers are ___________ if their sum is zero

additive inverses

a number and its opposite

reciprocals

two numbers are ____________ if their product is 1

multiplicative inverses

a number and its reciprocal

power

an expression written with an exponent and a base

square root

a number that is multiplied by itself to form a product

perfect square

a number whose positive square root is a whole number

natural numbers

the counting numbers: 1, 2, 3, ...

whole numbers

the natural numbers and zero: 0, 1, 2, 3, ...

integers

whole numbers and their opposites: -3, -2, -1, 0, 1, 2, 3, ...

rational numbers

a number that can be expressed in the form a/b, where a and b are both integers and b does not equal zero.

terminating decimals

rational numbers in decimal form that have a finite number of digits: 1.5, 2.75, 4.0

repeating decimals

rational numbers in decimal form that have a block of one or more digits that repeats continuously

irrational numbers

a number that cannot be expressed in the form a/b. They include square roots of whole numbers that are not perfect squares and nonterminating decimals that do not repeat.

order of operations

PEMDAS.....parenthesis, exponents, multiplication/division from left to right, addition/subtraction from left to right

terms

the parts of an expression that are to be added or subtracted

like terms

terms that contain the same variables raised to the same powers

Commutative Property

you can add numbers in any order and multiply numbers in any order

Associative Property

when you are only adding or multiplying, you can group any of the numbers together

Distributive Property

you can multiply a number by a sum or multiply by each number in the sum and then add...the result is the same

coefficient

a number multiplied by a variable

coordinate plane

formed by the intersection of two perpendicular number lines called axes

axes

two perpendicular number lines that form the coordinate plane

origin

the point of intersection on the coordinate plane, which is 0

x-axis

the horizontal number line

y-axis

the vertical number line

ordered pair

used to describe a point on the coordinate plane and consists of an x-coordinate and a y-coordinate and is written (x, y)

x-coordinate

tells how many units to move left or right from the origin

y-coordinate

tells how many units to move up or down from the origin

quadrants

the axes divide the coordinate plane into four ________

input

the value substituted for x in a function

output

the value generated for y in a function