How 'Anumber less than another number by 7' can be expressed using letters TES.
Answers
KEY TAKEAWAYS
Key Points
An inequality describes a relationship between two different values.
The notation a<ba<b means that aa is strictly smaller in size than bb, while the notation a>ba>b means that aa is strictly greater than bb.
The notion a≤ba≤b means that aa is less than or equal to bb, while the notation a≥ba≥b means that aa is greater than or equal to bb.
Inequalities are particularly useful for solving problems involving minimum or maximum possible values.
Key Terms
number line: A visual representation of the set of real numbers as a series of points.
inequality: A statement that of two quantities one is specifically less than or greater than another.
In mathematics, inequalities are used to compare the relative size of values. They can be used to compare integers, variables, and various other algebraic expressions. A description of different types of inequalities follows.
Strict Inequalities
A strict inequality is a relation that holds between two values when they are different. In the same way that equations use an equals sign, =, to show that two values are equal, inequalities use signs to show that two values are not equal and to describe their relationship. The strict inequality symbols are << and >>.
Strict inequalities differ from the notation a≠ba≠b, which means that a is not equal to bb. The ≠≠ symbol does not say that one value is greater than the other or even that they can be compared in size.
In the two types of strict inequalities, aa is not equal to bb. To compare the size of the values, there are two types of relations:
The notation a<ba<b means that aa is less than bb.
The notation a>ba>b means that aa is greater than bb.
The meaning of these symbols can be easily remembered by noting that the “bigger” side of the inequality symbol (the open side) faces the larger number. The “smaller” side of the symbol (the point) faces the smaller number.
The above relations can be demonstrated on a number line. Recall that the values on a number line increase as you move to the right. The following therefore represents the relation aa is less than bb:

a<ba<b
aa is to the left of bb on this number line.
and the following demonstrates aa being greater than bb:

a>ba>b
aa is to the right of bb on this number line.