Learning Resource Type

Classroom Resource

Solving Linear Equations with Negative Numbers

Subject Area

Mathematics

Grade(s)

6, 7

Overview

Solve a linear equation that has negative numbers and a variable. This video focuses on using inverse operations to solve for a variable.

This video was submitted through the Innovation Math Challenge, a contest open to professional and nonprofessional producers and is part of the Math at the Core: Middle School collection.

    Mathematics (2019) Grade(s): 6

    MA19.6.15

    Write, read, and evaluate expressions in which letters represent numbers in real-world contexts.

    Unpacked Content

    UP:MA19.6.15

    Vocabulary

    • Expressions
    • Term
    • Coefficient
    • Sum
    • Product
    • Factor
    • Quotient
    • Variable
    • Constant
    • Difference
    • Evaluate
    • Order of Operations
    • Exponent
    • Absolute Value

    Knowledge

    Students know:
    • Correct usage of mathematical symbolism to model the terms sum, term, product, factor, quotient, variable, difference, constant, and coefficient when they appear in verbally stated contexts.
    • Conventions for order of operations.
    • Convention of using juxtaposition (5A or xy) to indicate multiplication.

    Skills

    Students are able to:
    • Translate fluently between verbally stated situations and algebraic models of the situation.
    • Use operations (addition, subtraction, multiplication, division, and exponentiation) fluently with the conventions of parentheses and order of operations to evaluate expressions for specific values of variables in expressions.
    • Use terminology related to algebraic expressions such as sum, term, product, factor, quotient, or coefficient, to communicate the meanings of the expression and the parts of the expression.

    Understanding

    Students understand that:
    • The structure of mathematics allows for terminology and techniques used with numerical expressions to be used in an analogous way with algebraic expressions, (the sum of 3 and 4 is written as 3 + 4, so the sum of 3 and y is written as 3 + y).
    • When language is ambiguous about the meaning of a mathematical expression grouping, symbols and order of operations conventions are used to communicate the meaning clearly.
    • Moving fluently among representations of mathematical situations (words, numbers, symbols, etc.), as needed for a given situation, allows a user of mathematics to make sense of the situation and choose appropriate and efficient paths to solutions.
    Mathematics (2019) Grade(s): 7

    MA19.7.9

    Use variables to represent quantities in real-world or mathematical problems and construct algebraic expressions, equations, and inequalities to solve problems by reasoning about the quantities.

    Unpacked Content

    UP:MA19.7.9

    Vocabulary

    • Algebraic expressions
    • Equations
    • Inequalities
    • Greater than
    • Greater than or equal to
    • less than
    • less than or equal to

    Knowledge

    Students know:
    • p(x + q) = px + pq, where p and q are specific rational numbers.
    • When multiplying or dividing both sides of an inequality by a negative number, every term must change signs and the inequality symbol reversed.
    • In the graph of an inequality, the endpoint will be a closed circle indicating the number is included in the solution set (≤ or ≥) or an open circle indicating the number is not included in the solution set ( ).

    Skills

    Students are able to:
    • use variables to represent quantities in a real-world or mathematical problem.
    • Construct equations (px + q = r and p(x + q) = r) to solve problems by reasoning about the quantities.
    • Construct simple inequalities (px + q > r or px + q
    • Graph the solution set of an inequality.

    Understanding

    Students understand that:
    • Real-world problems can be represented through algebraic expressions, equations, and inequalities.
    • Why the inequality symbol reverses when multiplying or dividing both sides of an inequality by a negative number.
    Link to Resource

    CR Resource Type

    Audio/Video

    Resource Provider

    PBS
    Accessibility
    License

    License Type

    PD
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