3. Which of the following points shows a solution to the simultaneous inequalities y > 12x + 5 and y < −2x + 1?

A) (1,5.5)
B) (−5,5)
C) (−1.6,4.2)
D) (4,8)

4. Select a true statement to describe the graphed system of inequalities.
A) The system has infinite solutions.
B) The system has no solutions.
C) The system has two solutions.
D) The system has one solution.

1 answer

To determine the solutions to the simultaneous inequalities \(y > 12x + 5\) and \(y < -2x + 1\), we can analyze the given options by substituting the \(x\) and \(y\) values from each point into both inequalities.

  1. For point A \((1, 5.5)\):

    • Check \(y > 12x + 5\): \[ 5.5 > 12(1) + 5 \] \[ 5.5 > 12 + 5 \] \[ 5.5 > 17 \] (False)
    • Since the first inequality is false, A is not a solution.
  2. For point B \((-5, 5)\):

    • Check \(y > 12x + 5\): \[ 5 > 12(-5) + 5 \] \[ 5 > -60 + 5 \] \[ 5 > -55 \] (True)
    • Check \(y < -2x + 1\): \[ 5 < -2(-5) + 1 \] \[ 5 < 10 + 1 \] \[ 5 < 11 \] (True)
    • Since both inequalities are true, B is a solution.
  3. For point C \((-1.6, 4.2)\):

    • Check \(y > 12x + 5\): \[ 4.2 > 12(-1.6) + 5 \] \[ 4.2 > -19.2 + 5 \] \[ 4.2 > -14.2 \] (True)
    • Check \(y < -2x + 1\): \[ 4.2 < -2(-1.6) + 1 \] \[ 4.2 < 3.2 + 1 \] \[ 4.2 < 4.2 \] (False)
    • Since the second inequality is false, C is not a solution.
  4. For point D \((4, 8)\):

    • Check \(y > 12x + 5\): \[ 8 > 12(4) + 5 \] \[ 8 > 48 + 5 \] \[ 8 > 53 \] (False)
    • Since the first inequality is false, D is not a solution.

The only point that satisfies both inequalities is: B) (-5, 5).

Now, for the second part regarding the system of inequalities:

Since the two inequalities represent two lines that have a certain area between them, we can assume:

  • The inequality \(y > 12x + 5\) represents the area above the line \(y = 12x + 5\).
  • The inequality \(y < -2x + 1\) represents the area below the line \(y = -2x + 1\).

Given that the two areas (for the systems of inequalities) are distinct, and provided that one side limits the solutions of the other, it’s correct to conclude:

A) The system has infinite solutions.

So, in summary:

  • Point showing a solution: B) (−5, 5).
  • True statement about the system of inequalities: A) The system has infinite solutions.