Download Notes - Ordered Pairs Holt text 3-1 (p. 118) Ordered Pairs

Notes - Ordered Pairs
Holt text 3-1
(p. 118) Ordered Pairs- (x,y)
· a pair of numbers that can be used to locate a point on a
coordinate plane
· a solution of a two-variable can be written as an ordered pair
* this will make more sense after we do the example problems
Skill- Finding if an ordered pair is a solution to an equation.
To find if an ordered pair is a solution to an equation,
· Substitute the x & y values from the ordered pair into the
equation
· Simplify.
· If you get the same number on both sides of the =, the ordered
pair is a solution. See examples below
Examples - Holt page 120 # 1-4
Are the followiing ordered pairs solutions to the equation
y = 2x- 4
1. (3, 2) 2. (-4, 5)
2 = 2(3) -4
5 = 2(-4) -4
2 = 6-4 5 = -8- 4
2=2 5 = -12
Yes, (3,2) is a solution No, (-4,5) isn’t a
solution 3. (6,8) 8 = 2(6)-4
8 = 12-4
8=8 Yes (6,8) is a solution
4. (2,0)
0 = 2(2)-4
0 = 4-4
0=0
Yes (2,0) is a solution
Definitions
1. Coordinate Plane- A plane formed by the intersection of a horizontal number
line called the x-axis and a vertical number line called the y-axis.
2. x axis The horizontal axis on a coordinate plane.
3. y axis The vertical axis on a coordinate plane.
4. Quadrants- The four sections of a coordinate plane, separated by the x- and
y-axes.
5. x coordinate- The first number in an ordered pair; it tells the distance to move
right or left from the origin
6. y coordinate- The second number in an ordered pair; it tells to move up or
down.
7. Origin- The point where the x-axis and y-axis intersect on the coordinate plane;
located at (0, 0).
8. Graph of an Equation- A graph of the set of ordered pairs that are solutions
of the equation.