Inequality Fundamentals
When working with inequalities, you can add or subtract any number from both sides without changing the relationship. For multiplication and division, things get interesting - if you multiply or divide by a positive number, the inequality stays the same, but with a negative number, you need to flip the sign!
Compound inequalities combine two conditions using "and" or "or." For example, 2 < x ≤ 5 means x is greater than 2 AND less than or equal to 5. When graphing inequalities on a number line, use an open circle for < or > (showing exclusion) and a closed circle for ≤ or ≥ (showing inclusion).
Systems of inequalities involve multiple conditions that must be satisfied simultaneously. To solve these, you'll graph each inequality and identify where their solutions overlap, creating a region that works for all conditions.
Pro Tip: When solving inequalities, always test a value in your solution to verify it works! This quick check can save you from careless mistakes.