few_shots: 
Example:
Concept/skill: 
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.

Problem/activity:
Problem 1
The table below contains single equations in a single variable, single equations in two variables, and pairs of simultaneous equations in two variables. Check the appropriate box to show whether there is no solution, exactly 1 solution, or if there is an infinite number of solutions.
|                                                          | **           No solution          ** | **           Exactly 1 solution          ** | **           Infinite number of solutions          ** |
|----------------------------------------------------------|--------------------------------------|---------------------------------------------|-------------------------------------------------------|
|                       $${9=4x+7}$$                       |                                      |                                             |                                                       |
|                       $${y=3y+5}$$                       |                                      |                                             |                                                       |
|                    $${y={x\over2}}$$                     |                                      |                                             |                                                       |
|                     $${3x+6y-9=0}$$                      |                                      |                                             |                                                       |
|    $${x=y}$$                        $${1.25x=1.25y}$$    |                                      |                                             |                                                       |
| $${9.9=6x+8y}$$                        $${9x=2.5y-8.8}$$ |                                      |                                             |                                                       |
| $${11x-2y=1.5}$$                        $${11x-2y=2.5}$$ |                                      |                                             |                                                       |
Problem 2
Kim has a small container and a large container as shown.
[IMG]
It takes 16 of the small containers to fill the large container. Three small containers leave 1.95 gallons of space in the big container.
What is the size of each of the two containers?


Answer: 
No. Completing neither of these problems requires replacing one equation by the sum of that equation and a multiple of the other equation.

Now, determine whether the following problem or activity can enable students to understand the concepts or skills in the provided description.

shot_info: fl_problem_001392_neg_0

8
standard_description: Compose two-dimensional shapes (rectangles, squares, trapezoids, triangles, half-circles, and quarter-circles) or three-dimensional shapes (cubes, right rectangular prisms, right circular cones, and right circular cylinders) to create a composite shape, and compose new shapes from the composite shape. (Students do not need to learn formal names such as “right rectangular prism.”)
problem_activity: Activity
The purpose of this activity is for students to practice identifying the parts of a linear equation that affect specific features of its graph, specifically the slope and
\(y\)
-intercept. This will be useful when students make connections between two-variable linear equations and their graphs and situations that they represent in an associated Algebra 1 lesson.
Student Facing
For each equation, identify the slope and
\(y\)
-intercept of its graph.
\(y = 3x-8\)
\(y = 10-2x\)
\(y = \frac{x}{2} + 1\)
\(y + 1 = 9x\)
\(y = \frac{1}{3}(9x + 12)\)
Student Response
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Activity Synthesis
Discuss the slopes and
\(y\)
-intercepts and how they can be used. Here are discussion questions:
"How do you find the slope and
\(y\)
-intercept for the graph of a linear equation written in standard form like
\(\text-3x+y=\text-8\)
?" (Substitute 0 for
\(x\)
and solve for
\(y\)
.)
"The rate of change in a situation corresponds to what part of the graph?" (The rate of change corresponds to the slope of a graph.)
"Why is it useful to know the
\(y\)
-intercept and slope?" (The
\(y\)
-intercept and slope can make it very easy to create a graph from an equation because we know the key features. Also, they are useful to know in understanding a situation and the relationships between each quantity involved.)


aligns: no