standard_description: Construct a function to model a linear relationship between two quantities. Determine the rate of change and initial value of the function from a description of a relationship or from two (x, y) values, including reading these from a table or from a graph. Interpret the rate of change and initial value of a linear function in terms of the situation it models, and in terms of its graph or a table of values.
problem_activity: A system of linear equations is represented in the graph below.
[IMG]
a.   Write the two equations that represent this system.
b.   What is the solution to the system? Prove this algebraically.


aligns: no