**Unit 2 "Reasoning with Equations and Inequalities"**

__Key Standards__

Understand solving equations as a process of reasoning and explain the reasoningUnderstand solving equations as a process of reasoning and explain the reasoning

**MCC9**

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**12.A.REI.1**

Explain each step in solving a simple equation as following from the equality of numbers asserted at the previous step, starting from the assumption that the original equation has a solution. Construct a viable argument to justify a solution method.

Solve equations and inequalities in one variableSolve equations and inequalities in one variable

**MCC9**

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**12.A.REI.3**

Solve linear equations and inequalities in one variable, including equations with coefficients represented by letters.

Solve systems of equations

Solve systems of equations

**MCC9**

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**12.A.REI.5**

Prove that, given a system of two equations in two variables, replacing one equation by the sum of that equation and a multiple of the other produces a system with the same solutions.

**MCC9**

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**12.A.REI.6**

Solve systems of linear equations exactly and approximately (e.g., with graphs), focusing on pairs of linear equations in two variables.

__Represent and solve equations and inequalities graphically__**MCC9**

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**12.A.REI.12**

Graph the solutions to a linear inequality in two variables as a half‐plane (excluding the boundary in the case of a strict inequality), and graph the solution set to a system of linear inequalities in two variables as the intersection of the corresponding half‐planes.