(x, y)

In Algebra, x and y stand for UNKNOWN numbers:

Example: 5 + x = 9 ---> 5 + ? = 9 ----> 5 + 4 = 9, so x = 4.

Example, 3x = 9 or 3(?) = 9

Since 3(3) = 9, the x stands for 3.

Example: 9/x = 3 or 9 ÷ ? = 3

Since 9/3 = 3 or 9 ÷ 3 = 3, x stands for 3.

Example: Libelle needs a party gift for each of the guests at her birthday party.

At first, the number of gifts needed is UNKNOWN!

Libelle needs x number of gifts.

The number of gifts needed will vary

depending on how many guests are coming.

If 12 guests come, x = 12, because she'll need 12 gifts.

If 10 guests come, x = 10, because she'll need 10 gifts.

In this case, x is called a VARIABLE because its VALUE CHANGES with the circumstances. The VALUE of x VARIES depending on the number of guests who come, and at first, the value of x is unknown. When the invited guests say they are coming, Libelle will make a list of people coming and will add it up to find out the value of x, which is the number of gifts needed for her guests.

In Algebra, points are plotted on a coordinate grid. This is how you find places on a map.

The points are stored in parentheses and x is always first, then y: (x, y).

The points are called co ord in ates because they (go together) to mark a spot on the grid.

co means together (x, y)

ordinate means in order (x, y)

(x, y) = (5,4) =

(first walk the x across the floor ruler 5 spots, from that spot, now go up the y ruler 4 spaces). The coordinate point is the intersection of the 2 lines.