Using the properties of inequality, justify both steps in solving the inequality 2/5m - 7 less than or equal to 17

1 answer

To solve the inequality \( \frac{2}{5}m - 7 \leq 17 \), we can follow these steps while justifying each step using properties of inequalities:

Step 1: Add 7 to both sides.

Justification: When you add the same value to both sides of an inequality, the inequality sign remains the same.

Starting with the original inequality:

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

Add 7 to both sides:

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

This simplifies to:

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


Step 2: Multiply both sides by \( \frac{5}{2} \).

Justification: When you multiply both sides of an inequality by a positive number, the inequality sign remains the same.

Multiply both sides by \( \frac{5}{2} \):

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

The left side simplifies as follows:

\[ m \leq \frac{120}{2} \]

This simplifies to:

\[ m \leq 60 \]


Conclusion: The solution to the inequality \( \frac{2}{5}m - 7 \leq 17 \) is \( m \leq 60 \). Both steps maintain the inequality correctly, as justified above.