HSA.REI.C.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.

HSA.REI.C.6 – Solve systems of linear equations exactly and approximately (e.g., with graphs), focusing on pairs of linear equations in two variables.

TEKS (2015-16)

A.2(I) – write systems of two linear equations given a table of values, a graph, and a verbal description

A.3(F) – graph systems of two linear equations in two variables on the coordinate plane and determine the solutions if they exist

A.3(G) – estimate graphically the solutions to systems of two linear equations with two variables in real-world problems

A.5(C) – solve systems of two linear equations with two variables for mathematical and real-world problems