# 2Tvwo §11.4 AxB=0

§11.4 A x B = 0
All the 'factorising', done in paragraphs 1, 2 and 3,
will be used several times again.
So you see that a chapter is not a bunch of loose items!

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Slide 1: Slide
WiskundeMiddelbare schoolvwoLeerjaar 2

This lesson contains 30 slides, with interactive quizzes and text slides. Lesson duration is: 50 min

## Items in this lesson

§11.4 A x B = 0
All the 'factorising', done in paragraphs 1, 2 and 3,
will be used several times again.
So you see that a chapter is not a bunch of loose items!

#### Slide 2 -Slide

Recap on §11.2 and §11.3
To work your way much easier through §11.3,
first we look back shortly.

#### Slide 5 -Slide

+ Open your Notebook and Textbook on p.178/179:     §11.4 A x B = 0
+ Watch the equations from exercise 28
+ Compare them to those of exercise 35, p.183!
+ What's the main difference between them?
timer
0:30

#### Slide 6 -Slide

Main difference between equations from 28 and 35 is:
.............................

#### Slide 7 -Mind map

+ The equations from 28 all end with:  ................. = 0
+ The equations from 35 don't end with .............. = 0.

This means that the equations from §11.4, today's paragraph, are easier to solve. Just watch the next slides!

#### Slide 8 -Slide

Solving an Equation that is a Product:
A x B = 0.  This equation can only be 0, when
A = 0  or  B = 0
In the next example the 'A' and the 'B' are expressions with 'x'.
Just watch!

#### Slide 11 -Slide

1.  Copy this exercise in your Notebook
2.Solve the equation             3. Finally key in your answers in the next slide
timer
1:00

#### Slide 12 -Slide

A. 0 and -7 B. 2 and -7
C. 0 and 2 D. -2 and 7

A
0 and -7
B
2 and -7
C
0 and 2
D
-2 and 7

#### Slide 14 -Slide

Homework -part 1
Work on exercises:
28 and further (so you may skip 26 and 27)
later this LessonUp will be continued!

#### Slide 15 -Slide

Now a connection will be made between:

2nd:     graphs for quadratic formulas, so parabolas!
By doing 30 together, you will learn to do the 2nd half of the paragraph.

#### Slide 16 -Slide

+ Think about it for a while.

timer
0:20

timer
1:00

#### Slide 20 -Slide

Solution:

In the next slide, this equation will be solved.

#### Slide 21 -Slide

1. Copy the equation in your Notebook and
2. Factorise it.

If you forgot how to Factorise a Trinomial,
look it up on p.175: Method!
timer
1:00

SOLUTION:

#### Slide 23 -Slide

at 30a we saw that the graph intersects the x-axis at x = -1 and x = 2.
Do you now get the same outcomes?!
timer
1:00

#### Slide 24 -Slide

SOLUTION on the right:
(Do you remember that we found
the same outcome with the graph?)

Next comes
a bit of Theory,
summarising all this!

#### Slide 26 -Slide

This is a FOTOVRAAG !
+ Make 31 a in your Notebook
+ Make a picture of your work
+ Send it in, in the next slide and
+ We get a collection of your Solutions!

#### Slide 27 -Slide

31a:

For which values of x does the graph intersect the x-axis?
y=x2+3x18
timer
1:00

x2+3x18=0
(x+6)(x3)=0
X+6=0
x3=0
x=6
x=3
x+6=0

#### Slide 29 -Slide

Homework-part 2
Make:      §11.4    A x B = 0
Do exercises:
28 t/m 33      (So you may skip 26 and 27.)
1. Make it                2. Correct it with the Solutionsbook
3. Send in your results in GC.