What is the solution set of: 3x - 2 = 7 and 4x + 5 < 21

1 answer

To find the solution set of the equations \(3x - 2 = 7\) and the inequality \(4x + 5 < 21\), we will solve each separately.

  1. Solve the equation \(3x - 2 = 7\):

    \[ 3x - 2 = 7 \]

    First, add 2 to both sides:

    \[ 3x = 7 + 2 \] \[ 3x = 9 \]

    Now, divide both sides by 3:

    \[ x = \frac{9}{3} = 3 \]

  2. Solve the inequality \(4x + 5 < 21\):

    \[ 4x + 5 < 21 \]

    First, subtract 5 from both sides:

    \[ 4x < 21 - 5 \] \[ 4x < 16 \]

    Now, divide both sides by 4:

    \[ x < \frac{16}{4} = 4 \]

  3. Combine the results:

    The solution set for the equation is \(x = 3\) and for the inequality, it is \(x < 4\).

    Since \(3\) is less than \(4\), it satisfies the inequality.

    Therefore, the solution set including both the equation and the inequality is:

    \[ x = 3 \]

In conclusion, the solution set is \( { 3 } \).