Definition: An inequality is a mathematical statement that compares two expressions using less than, greater than, at most, or at least instead of an equal sign.
What is an inequality?
An inequality shows that two values are not necessarily equal. The symbols are < (less than), > (greater than), <= (less than or equal to, at most), and >= (greater than or equal to, at least).
How many solutions are there?
Usually many. The inequality x > 5 is true for 5.1, 6, 100, and infinitely many more. On a number line, draw an open circle at 5 and shade to the right. For x >= 5, use a closed circle because 5 itself is included.
How do you read real situations?
Mathbot’s elevator holds at most 8 people. If p is the number of people, then p <= 8. A movie requiring riders to be at least 48 inches tall gives h >= 48.
How do you solve a one-step inequality?
Solve like an equation. For y + 9 < 20, subtract 9 from both sides to get y < 11.
What is the usual error?
Using the wrong circle, or reversing the symbol. Remember that the open end of the symbol faces the larger value.