Systems of Linear Equations Unit Test

6 of 146 of 14 Items

Question
Which of these graphs shows that the linear system 3x+2y=12
and 6x+4y=24
has an infinite number of solutions?(1 point)
Responses

A coordinate plane with 4 quadrants shows x and y axes ranging from negative 10 to 10 in unit increments. Two intersecting lines are plotted on the plane. A solid downward slanting line passes through the points left parenthesis negative 6 comma 3 right parenthesis and left parenthesis negative 4 comma 0 right parenthesis. A dotted upward slanting line passes through the points left parenthesis 0 comma negative 6 right parenthesis and left parenthesis 6 comma 4 right parenthesis.
Image with alt text: A coordinate plane with 4 quadrants shows x and y axes ranging from negative 10 to 10 in unit increments. Two intersecting lines are plotted on the plane. A solid downward slanting line passes through the points left parenthesis negative 6 comma 3 right parenthesis and left parenthesis negative 4 comma 0 right parenthesis. A dotted upward slanting line passes through the points left parenthesis 0 comma negative 6 right parenthesis and left parenthesis 6 comma 4 right parenthesis.

A coordinate plane with 4 quadrants shows x and y axes ranging from negative 10 to 10 in unit increments. A line is plotted on the plane. A downward slanting line with arrows at both ends passes through the points left parenthesis 0 comma 6 right parenthesis and left parenthesis 4 comma 0 right parenthesis.
Image with alt text: A coordinate plane with 4 quadrants shows x and y axes ranging from negative 10 to 10 in unit increments. A line is plotted on the plane. A downward slanting line with arrows at both ends passes through the points left parenthesis 0 comma 6 right parenthesis and left parenthesis 4 comma 0 right parenthesis.

A coordinate plane with 4 quadrants shows x and y axes ranging from negative 10 to 10 in unit increments. Two parallel lines are plotted on the plane. A dotted downward slanting line with arrows at both ends passes through the points left parenthesis negative 4 comma 0 right parenthesis and left parenthesis 0 comma negative 6 right parenthesis. A solid downward slanting line with arrows at both ends passes through the points left parenthesis 0 comma 6 right parenthesis and left parenthesis 4 comma 0 right parenthesis.
Image with alt text: A coordinate plane with 4 quadrants shows x and y axes ranging from negative 10 to 10 in unit increments. Two parallel lines are plotted on the plane. A dotted downward slanting line with arrows at both ends passes through the points left parenthesis negative 4 comma 0 right parenthesis and left parenthesis 0 comma negative 6 right parenthesis. A solid downward slanting line with arrows at both ends passes through the points left parenthesis 0 comma 6 right parenthesis and left parenthesis 4 comma 0 right parenthesis.

A coordinate plane with 4 quadrants shows x and y axes ranging from negative 10 to 10 in unit increments. A line is plotted on the plane. A downward slanting line with arrows at both ends passes through the points left parenthesis negative 10 comma 9 right parenthesis and left parenthesis negative 4 comma 0 right parenthesis.

must pick 1st 2nd 3rd or 4th option

1 answer

To determine which graph shows that the system of linear equations \(3x + 2y = 12\) and \(6x + 4y = 24\) has an infinite number of solutions, we need to analyze the equations.

The second equation \(6x + 4y = 24\) can be simplified by dividing everything by 2, which yields:

\[ 3x + 2y = 12 \]

This means that both equations actually represent the same line. Therefore, they are equivalent and have infinitely many solutions since they overlap entirely.

Given this understanding, the graph that represents the same line for both equations is the one with two identical lines (i.e., one solid and one dotted) that coincide with each other.

Let's assess the options:

  1. The first option shows two intersecting lines, which means a unique solution.
  2. The second option shows a single line, which represents one equation.
  3. The third option shows two parallel lines, which indicates no solution.
  4. The fourth option shows one line, also representing one equation.

Based on this analysis, none of the descriptions provided perfectly match the representation of coinciding lines indicating an infinite number of solutions. If you are forced to choose among these, the closest possible representation for infinite solutions might typically appear as two overlapping lines, but if the scenarios don’t perfectly fit, there may be an error in the available options.

In conclusion, if the goal is to identify equivalent representations, the first option would indicate a misconception since they intersect. However, based on the context of depicting the scenario correctly, it can be confirmed that there should be selections that show lines coinciding, which are not found in the given options.