# 1718 WB1Z CH12 Lesson 8

Which exercises should I dicuss on the board?
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In deze les zitten 18 slides, met interactieve quizzen en tekstslides.

Lesduur is: 50 min

## Onderdelen in deze les

Which exercises should I dicuss on the board?

Overview CH12

#### Slide 2 -Tekstslide

Combining like terms
You can only add or subtract like terms. Terms are called like terms if they have the same variable as a base and the same exponent.

#### Slide 3 -Tekstslide

Multiplying factors
When multiplying factors you multiply the numbers by each other and you multiply the variables by each other.
If you multiply powers with the same variable as a base, you can add the exponents.

#### Slide 4 -Tekstslide

Writing formulas shorter
2) Then combine the like terms (addition and subtraction)
3) Write terms as 1a or -1a shorter as a or -a
Example:

#### Slide 5 -Tekstslide

Solve equations using cards
1) Simplify the equation if needed
2) Solve the equation using cards, write down the steps!
Example:
-4a + 7 - 6a = 42
-10a + 7 = 42               (simplify the equation)
-10a = 35                      (use cards method)
a = -3.5                          (solution)

#### Slide 6 -Tekstslide

Powers and negative numbers

#### Slide 7 -Tekstslide

The axes divide the coordinate
The axes themselves are NOT

counterclockwise

#### Slide 8 -Tekstslide

Making linear formulas
How to make a linear formula from a graph.
1) Make a table, horizontal axis = top row, vertical axis = bottom row, fill in easy to read off points on the graph.
2) Find the start value (value on bottom row when top row = 0)
3) Calculate the gradient (increase in bottom row when the top row increases by 1)
4) Make a formula:
vertical variable = start value + gradient x horizontal variable

#### Slide 9 -Tekstslide

Start value = 4

Formula:
height = 4 + 0.8 x distance
h = 4 + 0.8d

#### Slide 10 -Tekstslide

Making linear formulas
How to make a linear formula from a story

1) Find the start value
4) Make a formula:
variable you calculate = start value + gradient x variable used for calculation

#### Slide 11 -Tekstslide

Nimah is studying her French vocabulary. She has already memorised 100 words. It takes her an half an hour to memorise 20 more words. Make a formula to calculate how many words (w) Nimah knows after studying for a given number of hours (t).

Start value = 100
Gradient = 40 (20 per half hour so 40 per hour)
Formula:            w = 100 + 40t

#### Slide 12 -Tekstslide

Plotting a parabola
The graph of a quadratic formula is called a parabola.
If you want to plot a parabola, make a table first!

#### Slide 13 -Tekstslide

Plotting a parabola

Use brackets
when filling in
negative numbers!

#### Slide 14 -Tekstslide

Plotting a parabola

Parabolas have reflection symmetry.

#### Slide 15 -Tekstslide

Find out if a point lies on a graph
1) Fill in the first coordinate in the formula
2) Calculate the result
3) Compare to given second coordinate

Does (-2, 3) lie on the graph of a = -3b + 12?
a = -3 x -2 + 12 = 18
No, (-2, 3) does not lie on the graph.

#### Slide 16 -Tekstslide

HW Tuesday
Make and correct:
Practice Test CH12 from your workbook

(No school on Monday, 4test CH12 on Friday)

#### Slide 17 -Tekstslide

Which theory should I explain again?