# What is a Set of Ordered Pairs?

This question aims to find the definition of an ordered pair. An ordered pair consists of two coordinates written in a specific order inside the parenthesis, where the x-coordinate is called abscissa and the y-coordinate is called ordinate.

These ordered pairs are generally used in graphs where they represent the position of points on the graph.

• These ordered pairs make the construction of graphs easy.
• Ordered pairs are used to locate the points on the graph.

Ordered pairs are represented as ($x$,$y$), where the abscissa of the ordered pair is the distance of a point on the x-axis from the origin, and the ordinate of the ordered pair is the distance of a point on the y-axis from the origin.

For example:

An ordered pair $A$= ($4$,$6$) is represented on the graph in the following way, where the value of $x$ is $4$, and the value of $y$ is $6$.

Figure 1

### Ordered Pairs in the Cartesian Plane

In a cartesian plane, the point at which the x-coordinate and y-coordinate are zero is called the origin. The distance of a point from the origin determines its numerical value. The x-axis is a horizontal line that determines the value of an independent variable, and the y-axis is the vertical line in a cartesian plane that determines the value of a dependent variable.

### Ordered Pairs in a Set

Insets, the abscissa of an ordered pair, is called the first element, and the ordinate of the ordered pair is called the second element. They are represented as:

$(a,b)\neq (b,a)$

This expression tells us the importance of order. Changing the order will make $b$ as abscissa and $a$ as ordinate.

### Equality of Ordered Pairs

Two ordered pairs  ($a$,$b$) and ($c$,$d$) are said to be equal when the corresponding first and second elements of these pairs are equal.

For example:

$a$=$c$ and $b$=$d$ then we will say that, ($a$,$b$)=($c$,$d$).

## Numerical Solution

Find the value of the $x$ and $y$ if the given ordered pairs are:

Given: $(x – 3 , y + 2) = (4 , 5)$

Required: Values of $x$ and $y$

Equating both ordered pairs give us:

$x = 4 + 3$

$y = 5 – 2$

$x = 7$

$y = 3$

## Example

Given:

$(5a – 4 , b + 1) = (3a , 3)$

Required: Values of $x$ and $y$

$5a – 4 = 3a$ $and$ $b + 1 = 3$

$5a – 3a = 4$

$b = 3 – 1$

$b = 2$

$2a = 4$

$a = 2$

Image/Mathematical drawings are created in Geogebra.