solution set of 3x-2=7 and 4x+5≤21

1 answer

To find the solution set for the equations \(3x - 2 = 7\) and the inequality \(4x + 5 \leq 21\), we need to solve each one separately.

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

  1. Add 2 to both sides: \[ 3x = 7 + 2 \] \[ 3x = 9 \]

  2. Divide both sides by 3: \[ x = \frac{9}{3} \] \[ x = 3 \]

Step 2: Solve the inequality \(4x + 5 \leq 21\)

  1. Subtract 5 from both sides: \[ 4x \leq 21 - 5 \] \[ 4x \leq 16 \]

  2. Divide both sides by 4: \[ x \leq \frac{16}{4} \] \[ x \leq 4 \]

Step 3: Combine the results

The solution to the equation gives us \(x = 3\). The solution to the inequality indicates that \(x\) can be any value less than or equal to 4.

Since 3 is less than or equal to 4, it satisfies the inequality.

Final Solution Set

Thus, the complete solution set is:

  • The equation \(3x - 2 = 7\) gives \(x = 3\).
  • The inequality \(4x + 5 \leq 21\) gives \(x \leq 4\).

Conclusion: The solution set that satisfies both the equation and the inequality is: \[ x = 3 \] And since it is also valid for the inequality, we state the final solution:

\[ { x | x = 3 \text{ and } x \leq 4 } \] or simply, \[ { 3 } \] Which is a subset of \( (-\infty, 4] \).