Using the properties of inequality, justify both steps in solving the inequality 2/5m−7≤17

.(4 points)

1 answer

To solve the inequality \( \frac{2}{5}m - 7 \leq 17 \), we will justify both steps using properties of inequalities.

Step 1: Isolate the term with \( m \)

Action: Add 7 to both sides of the inequality.

\[ \frac{2}{5}m - 7 + 7 \leq 17 + 7 \]

This simplifies to:

\[ \frac{2}{5}m \leq 24 \]

Justification: When we add the same value (in this case, 7) to both sides of an inequality, the direction of the inequality remains the same. This is a property of inequalities known as the "Addition Property of Inequality.”

Step 2: Solve for \( m \)

Action: Multiply both sides of the inequality by \( \frac{5}{2} \).

\[ \left(\frac{5}{2}\right) \cdot \frac{2}{5}m \leq 24 \cdot \left(\frac{5}{2}\right) \]

This simplifies to:

\[ m \leq 60 \]

Justification: When multiplying both sides of an inequality by a positive number (in this case, \( \frac{5}{2} \)), the direction of the inequality remains the same. This is known as the "Multiplication Property of Inequality."

Conclusion

Combining the justified steps, we have:

  1. \( \frac{2}{5}m - 7 \leq 17 \) → Add 7: \( \frac{2}{5}m \leq 24 \)
  2. Multiply by \( \frac{5}{2} \): \( m \leq 60 \)

Thus, the solution to the inequality is:

\[ m \leq 60 \]