Ch 4-5 Graphing Linear Equations

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Transcript Ch 4-5 Graphing Linear Equations

Graphing Linear Equations 1

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Graphing Linear Equations

A linear equation can be written in the standard form of a linear equation:

Ax

+

By

=

C

, where

A

≥ 0 ,

A

and

B

are not both zero

, and

A

,

B

and

C

are integers whose greatest common factor is 1 .

Identify Linear Equations

Determine whether is a linear equation. If so, write the equation in standard form.

First rewrite the equation so that the variables are on the same side of the equation.

Original equation Subtract

z

from each side.

Simplify.

Since written in the form has 3 different variables, it cannot be

Answer:

This is not a linear equation.

Identify Linear Equations

Determine whether is a linear equation. If so, write the equation in standard form.

Rewrite the equation so that both variables are on the same side.

Original equation Subtract

y

from each side.

Simplify.

Identify Linear Equations To write the equation with integer coefficients, multiply each term by 4 .

Original equation Multiply each side of the equation by 4 .

Simplify.

The equation is now in standard form where

Answer:

This is a linear equation.

Identify Linear Equations

Determine whether is a linear equation. If so, write the equation in standard form.

Since the GCF of 3 , 6 , and 27 is not 1 , the equation is not written in standard form. Divide each side by the GCF.

Original equation Factor the GCF.

Divide each side by 3 .

Simplify.

Answer:

The equation is now in standard form where

Identify Linear Equations

Determine whether is a linear equation. If so, write the equation in standard form.

To write the equation with integer coefficients, multiply each term by 4 .

Original equation Multiply each side of the equation by 4.

Simplify.

Answer:

The equation can be written as Therefore, it is a linear equation in standard form where

Identify Linear Equations

Determine whether each equation is a linear equation. If so, write the equation in standard form.

a.

Answer:

linear equation; 4

x

y

= 5

b.

Answer:

not a linear equation

c.

Answer:

linear equation;

d.

Answer:

linear equation;

Graphing Linear Equations

The graph of a linear equation is a line.

The line represents all the solutions of the linear equation.

Also, every ordered pair on this line satisfies the equation.

Graph by Making a Table

Graph

In order to find values for

y

equation for

y

.

more easily, solve the Original equation Add

x

to each side.

Simplify.

Graph by Making a Table Multiply each side by 2.

Simplify.

Select five values for the domain and make a table.

Then graph the ordered pairs.

x

–3 –1 0 2 3

y

–4 0 2 6 8 (

x

,

y

) (–3 , –4) (–1 , 0) (0 , 2) (2 , 6) (3 , 8)

Answer:

Graph by Making a Table When you graph the ordered pairs, a pattern begins to form. The domain of is the set of all real numbers, so there are an infinite number of solutions of the equation. Draw a line through the points. This line represents all the solutions of .

Answer:

Graph by Making a Table

.