Algebra, Equations, and Inequalities Flashcards
Algebra
The part of math that involves variables
Variable
A letter that represents either a specific number OR all numbers
In an expression, we’re trying to find patterns that are true for all numbers
In an equation, we’re trying to solve for a specific number
Constant
A number or symbol (like π) that doesn’t change in value
Ex:
5
x
6y^2
Term
A product of constants and variables, including powers of variables
Coefficient
The constant factor of a term
Note: when no coefficient is listed, the coefficient = 1
Ex: 6y^2 (coefficient is 6)
x^5 (coefficient is 1)
Expression
A collection of one or more terms joined by addition and subtraction
Ex:
x + y
Y^2 - x^2
Notice that expressions DONT have equal signs
Monomial
An expression with exactly one term
Ex: 5x^2
Trinomial
An expression with exactly 3 terms
X^2 - 2x + 3
Binomial
An expression with exactly two terms
X^2 + 4x
Polynomial
An expression with any number of terms involving one single variable
Linear
A term with a single power of a variable (ie: not explicitly written with an exponent)
Quadratic
A term with a square of a single variable
X^2 + 4x + 2
Cubic
A term with a cube of a single variable
X^3 + 2x^2 + 2
Linear Expression
The highest power of the variables is 1
- 17x is a linear monomial
- 3x - 5 is a linear binomial
-Notice, a linear binomial has one linear term and one constant term
Quadratic Expression
The highest power of the variable is 2
- 14x^2 is a quadratic monomial
- x^2 - 4 is a quadratic binomial (with one quadratic term and one constant term)
- x^2 + 8x is a quadratic binomial (with one quadratic term and one linear term)
- x^2 + x - 1 is a quadratic trinomial (with one quadratic term, one linear term, and one constant term)
Like Terms
1 algebraic simplification rule: we can combine like terms by addition or subtraction!
Any two terms with the same variable part. It they differ at all, they differ in coefficients.
We can only add or subtract like terms NOT terms with different variables or powers.
Notice also that multiplication is commutative, that is, the order of factors in multiplication doesn’t matter.
-5xy and 7yx are still like terms!
Adding an algebraic expression involving parentheses
We can simply remove the parentheses and combine like terms
X^3 - 3x^2 + 3x) + (x^3 + 3x^2 -3x
= 2x^3
Subtracting algebraic expressions involving parentheses
When a subtraction occurs in front of parentheses, we must first chance every sign inside the parentheses to it’s opposite (addition becomes subtraction and vice versa) and then combine like terms
(-3x^2 + 3x) - (3x^2 - 3x)
= -6x^2 + 6x
Square of a sum formula
(a + b)^2
Can find using FOIL
(a + b)(a + b) =
a^2 + ab + ba + b^2 =
a^2 + 2ab + b^2
Square of a difference formula
(a - b)^2
Can be found using FOIL
(a-b)(a-b) =
a^2 -ab - ba + b^ 2 =
a^2 -2ab + b^2
Distributive Law
P(Q + R) =
PQ + PR
Difference of Two Squares
(a+b)(a-b) =
a^2 + ab - ab + b^2 =
a^2 - b^2