• #### Proportions - Problem 4

##### Math›Algebra›Solving Equations
Technique for turning percent problems into proportions that can be solved with cross multiplication
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• #### Commutative, Associative - Concept

##### Math›Pre-Algebra›Properties of Numbers
Overview of the commutative and associative properties for addition and multiplication
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• #### Multiplying and Dividing - Concept

##### Math›Pre-Algebra›Whole Numbers
Looking at how multiplication represents repeated addition, as well as special cases of multiplying and dividing whole numbers
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• #### The Identity Matrix - Concept

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to determine the identity matrix of order n.
• #### Multiplying and Dividing - Problem 1

##### Math›Pre-Algebra›Whole Numbers
Using opposite operations to solve one step equations that involve multiplication or division of whole numbers
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• #### Scientific Notation - Problem 3

##### Math›Algebra 2›Exponents
How to evaluate products involving scientific notation.
• #### The Inverse of a Square Matrix - Concept

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to determine whether two matrices are inverses.
• #### Unit Vectors - Problem 2

##### Math›Precalculus›Vectors and Parametric Equations
How to find the unit vector that has the same direction as a given vector.
• #### Square Matrices - Concept

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to determine whether two matrices can be multiplied, and if so, what the dimensions of the product will be.
• #### Solving a Rational Equation - Problem 6

##### Math›Algebra 2›Rational Expressions and Functions
Solving rational equations using cross multiplication, checking for extraneous solutions
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• #### Solving and Graphing Multistep Inequalities - Problem 1

##### Math›Algebra›Solving and Graphing Inequalities
How to solve and graph multistep inequalities using multiplication and subtraction.
• #### Unit Vectors - Concept

##### Math›Precalculus›Vectors and Parametric Equations
How to express a vector algebraically in terms of the unit vectors i and j.
• #### Square Matrices - Problem 2

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to interpret 2x2 matrices as transformations.
• #### Multiplying and Distributing Radical Expressions - Problem 7

Multiplying radical expressions in fractions with coefficients, including simplifying before or after multiplication.
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• #### Multiplying and Dividing Rational Expressions - Problem 3

##### Math›Algebra 2›Rational Expressions and Functions
How to simplify a rational expression involving both multiplication and division.
• #### The Inverse of a Square Matrix - Problem 2

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to determine that a matrix has no inverse using row operations.
• #### The Midpoint and Distance Formulas in 3D - Concept

##### Math›Precalculus›Vectors and Parametric Equations
How to derive the formula for the midpoint of a segment in three dimensions.
• #### The Inverse of a Square Matrix - Problem 3

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to find the inverse of a square matrix of order 3 using row operations.
• #### Unit Vectors - Problem 1

##### Math›Precalculus›Vectors and Parametric Equations
How to convert a vector into component form when it is expressed in terms of the unit vectors i and j.
• #### The Inverse of a Square Matrix - Problem 1

##### Math›Precalculus›Systems of Linear Equations and Matrices
How to find the inverse of a square matrix of order 2 using row operations.