Math Problem Statement

Graph the system of equations and analyze their solutions: 1) 2y + x = 4 2) y = 3x + 9 Other questions involve selecting statements about solutions to systems of equations, determining if lines have infinitely many solutions, and analyzing graphs to identify solutions.

Solution

Let's go through the questions step by step.


Question 4

The system of equations provided is:

  1. 2y+x=42y + x = 4
  2. y=3x+9y = 3x + 9

Solution:
To graph the system:

  • Rewrite the first equation 2y+x=42y + x = 4 into slope-intercept form:
    2y=x+4y=12x+22y = -x + 4 \quad \Rightarrow \quad y = -\frac{1}{2}x + 2 This line has a slope of 12-\frac{1}{2} and a yy-intercept of 22.
  • The second equation is already in slope-intercept form:
    y=3x+9y = 3x + 9 This line has a slope of 33 and a yy-intercept of 99.

Graph these two lines:
The solution to the system is the point where these two lines intersect. Based on their slopes, they will intersect at exactly one point. Without graphing explicitly, solve algebraically:
Set 12x+2=3x+9-\frac{1}{2}x + 2 = 3x + 9:
12x3x=92-\frac{1}{2}x - 3x = 9 - 2 Combine like terms:
72x=7-\frac{7}{2}x = 7 Solve for xx:
x=2x = -2 Substitute x=2x = -2 into either equation (e.g., y=3x+9y = 3x + 9):
y=3(2)+9=6+9=3y = 3(-2) + 9 = -6 + 9 = 3 Solution: The lines intersect at (2,3)(-2, 3).


Question 5

Which statements describe the solution to a linear system of equations?

Correct answers:

  • A: The point(s) of intersection of the graphs of each equation.
  • E: A coordinate pair that makes both equations true.
  • F: A point on the graph of both lines.

Question 6

The given system is:

  1. 3xy=23x - y = 2
  2. 6x2y=46x - 2y = 4

Solution:
Notice that the second equation is a multiple of the first:
6x2y=2(3xy)=46x - 2y = 2(3x - y) = 4 This means the two equations represent the same line. Therefore, the system has infinitely many solutions because every point on the line satisfies both equations.


Question 7

Analyzing the graph:

  • Aniyah says the system has no solution because the lines do not cross and are growing apart.
  • Jessica says the system has a solution because the lines are not parallel.

From the graph, the lines are parallel because they have the same slope but different yy-intercepts. Parallel lines never intersect, so there is no solution.

Correct answer: Aniyah is correct because the lines are parallel.


Summary Answers:

  1. Question 4: Solution is (2,3)(-2, 3).
  2. Question 5: A, E, F are correct.
  3. Question 6: Infinitely many solutions (same line).
  4. Question 7: Aniyah is correct (no solution; lines are parallel).

Follow-up Questions:

  1. How do you identify parallel lines using slopes?
  2. What are the different possible solutions for systems of linear equations?
  3. How can you graph a linear equation given its slope and yy-intercept?
  4. Why do two identical equations represent infinitely many solutions?
  5. How do you solve a system of equations algebraically?

Tip:

To check if two lines are parallel, compare their slopes. If they are equal but the yy-intercepts differ, the lines are parallel and have no solution.

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Math Problem Analysis

Mathematical Concepts

Graphing Linear Equations
Solving Systems of Equations
Parallel Lines and Solutions
Slope-Intercept Form

Formulas

Slope-Intercept Form: y = mx + b
Solution of System: Intersection of two lines
Condition for Parallel Lines: Equal slopes, different y-intercepts

Theorems

Two lines with different slopes intersect at one point.
Parallel lines have no solutions.
Identical lines have infinitely many solutions.

Suitable Grade Level

Grade 8-10