Match the system of equations to the number of solutions it has.

y = 5x + 7 3y - 15x = 18 no, infinite or one solution
y = 3x + 6 y = -13x - 4 no, infinite or one solution
x - 2y = 6 3x - 6y = 18 no, infinite or one solution
y = 23x - 1 y = 23x - 2 no, infinite or one solution

1 answer

To determine the number of solutions for each system of equations, we can analyze the equations and see if they are parallel, identical, or intersecting lines.

  1. System: \(y = 5x + 7\)
    \(3y - 15x = 18\)

    • Rewrite the second equation: \[ 3y = 15x + 18 \implies y = 5x + 6 \]
    • Since the first equation is \(y = 5x + 7\) and now we have \(y = 5x + 6\), they are parallel lines (same slope, different intercepts).
      Solution: no solutions.
  2. System: \(y = 3x + 6\)
    \(y = -13x - 4\)

    • Both are in slope-intercept form with different slopes (3 and -13), so they will intersect at one point.
      Solution: one solution.
  3. System: \(x - 2y = 6\)
    \(3x - 6y = 18\)

    • Rewrite the second equation: \[ 3x - 6y = 18 \implies x - 2y = 6 \]
    • The second equation is a multiple of the first, so they represent the same line.
      Solution: infinite solutions.
  4. System: \(y = 23x - 1\)
    \(y = 23x - 2\)

    • These lines have the same slope (23) but different y-intercepts (-1 and -2), which means they are parallel.
      Solution: no solutions.

Summary of Solutions:

  1. \(y = 5x + 7\) and \(3y - 15x = 18\) - no solutions.
  2. \(y = 3x + 6\) and \(y = -13x - 4\) - one solution.
  3. \(x - 2y = 6\) and \(3x - 6y = 18\) - infinite solutions.
  4. \(y = 23x - 1\) and \(y = 23x - 2\) - no solutions.