## Parts of A Coordinate Grid

## Liner Relation

When plotted points on a coordinate grid form a straight line, it is called a **LINEAR RELATION**.

## Ordered Pairs & Table of Values

· Find a relationship in the table of values.

· Then find three more co-ordinates.

· Plot it and determine if its linear.

## Liner Relation –-Solving Graphically

For a car wash fundraiser Team A washes 2 cats per hours, starting at 7:00am. Team B begins washing cars at 9:00 am and washes 3 cars per hours.

Graph the car washing progress of each team.**POI **tells us –It is __when __ both teams have the same number of cars washed.__Definition__

Linear System – when you consider or look at two or more linear eq’ns at the

same time.

POI = Pont of Intersections – When the two line intercept /cross on the graph it is the co-ordinates found on both lines.

## Graphing with a Point and a Slope

The way you make a graph with a slope and a point is, first you plot the point and then you just add the slop.

m= slop= __rise__

run

## Standard Form Equation of A line

y = mx + b à slope intercept form

Ax + Bx + C = 0 à standard form

We know that we only need minimum of 2 points to draw a line

Example: 2x + 4y +8 = 0

· Find 2 ponits so that you can draw the line.

· The easiest point to choose are the x-intercept and the y-intercept.

** y–intercept**

__x–intercept__Lets find the y intercept first. Lets find the x–intercept next.

The x-coordinate for my y-intercept The y–coordinate for my x–coordinate

is zero. will

**Always be 0**.

Substatute zero into the eq’n whenever Substatute zero into the eq’n whenever

you see

__x__. you see

__y__.

2(0) + 4y + 8 = 0 2x + 4(0) + 8 = 0

4y + 8 – 8 = 0 – 8 2x + 8 – 8 = 0 – 8

__4y = –8__

**.**

__2x = –8__

**.**

4

**. .**the y–intercept is (0,–2) 2

**. .**the y–intercept is (0,–2)

y = –2 x = – 4

## Rearranging EQ’NS From One Form to Another.

__Ex.__ y = 3x + 1 àput it into standard form __Ex.__ x – 3y + 9 = 0 à put into slop form**Ax + Bx + C = 0 y = mx + b**

y = 3x + 1 x – 3y + 9 – 9 + 0 – 9

y – 3x – 1 = 3x – 3x + 1 – 1 x – x – 3y = –9 – x

y – 3x – 1 = 0 __–3y = –9 – x__

–3x + y – 1 = 0 –3

y = 3 + __1__x

A = –3 3

B = 1 y = __1__x + 3

C = –1 3