Consider the unfinished equation 12(x - 3) + 18 - Match the following expressions with the number of solutions the equation would have with that expression on the right-hand side. 3 points)

6(2x-3)
4(3x-3)
4(2x-3)

1 answer

To determine the number of solutions for the equation \(12(x - 3) + 18 = k\) for each expression on the right-hand side, we first simplify the left side.

Starting with the left-hand side:

\[ 12(x - 3) + 18 = 12x - 36 + 18 = 12x - 18 \]

Now we have the equation:

\[ 12x - 18 = k \]

We can solve for \(x\):

\[ 12x = k + 18 \] \[ x = \frac{k + 18}{12} \]

The number of solutions depends on the right-hand side expression \(k\). Each expression corresponds to a specific value of \(k\):

  1. For \(k = 6(2x - 3)\):

    \[ k = 6(2x - 3) = 12x - 18 \]

    Here, both sides are equal, so the equation \(12x - 18 = 12x - 18\) holds true for all \(x\). Thus, there are infinitely many solutions.

  2. For \(k = 4(3x - 3)\):

    \[ k = 4(3x - 3) = 12x - 12 \]

    Setting up the equation:

    \[ 12x - 18 = 12x - 12 \]

    Simplifying gives:

    \[ -18 \neq -12 \]

    Since this is a false statement, there are no solutions.

  3. For \(k = 4(2x - 3)\):

    \[ k = 4(2x - 3) = 8x - 12 \]

    Setting up the equation:

    \[ 12x - 18 = 8x - 12 \]

    Rearranging gives:

    \[ 12x - 8x = -12 + 18 \] \[ 4x = 6 \] \[ x = \frac{6}{4} = \frac{3}{2} \]

    This results in a single solution. Thus, there is one solution.

Summary of solutions:

  • \(6(2x-3)\): Infinitely many solutions
  • \(4(3x-3)\): No solutions
  • \(4(2x-3)\): One solution