Chapter 7 Linear Formulas

• Wiskunde
• Middelbare school
• havo
• Leerjaar 1

Linear formulas

Instructions

We are going to do a couple off quiz questions.

Please play along on your mobile phone.

Reken uit:
4²+2

1. 10
2. 12
3. 18
4. 36

A painter is asking € 25 per hour.
But also charges € 70 for brushes,
sanding paper etc.
What is the starting value?

1. € 25
2. € 45
3. € 70
4. € 95

A painter is asking € 25 per hour.
But also charges € 70 for brushes,
sanding paper etc.
What do you need to pay after two hours?

1. € 50
2. € 120
3. € 140
4. € 190

A painter is asking € 25 per hour.
But also charges € 70 for brushes,
sanding paper etc.
What is the correct formula?

1. 25 x time + 70 = amount
2. 70 + time x 25 = amount
3. amount = 70 + 25 x time
4. amount = time x 25 + 70

Drag and drop

Drag and drop the correct words and/of numbers to

make the right formula.

___ + ________ x ___ = ________ 

time

price

2

1

0,5

3

___ -  ________ x ___ = ________ 

time

length

8

4

100

20

___ + ________ x ___ = ________ 

time

distance

10

30

100

300

A:  ___ - time x ___ = amount

B:  ___ + time x ___ = amount

60

360

10

20

15

30

After how many days are the graphs at the same height?

60 + time x 15 = amount
Calculate the amount when time is 20
Which is the correct way to write it down?

1. 60 + 20 = 80 80 x 15 = 1200
2. 20 x 15 = 300 + 60 = 360
3. 60 + 20 x 15 = 60 + 300 = 360
4. 360

Which of these five subjects do you find most difficult?

Make a formula from a description

Plot a graph for a formula

See from a formula if the graph is rising or falling

Make a formula for a linear graph

Check if you read off a point of intersection correctly

Make a formula from a description	E1, E2
Plot a graph for a formula	E3, E4
See from a formula if the graph is rising or falling	E5
Make a formula for a linear graph	E6
Check if you read off a point of intersection correctly	E7

Pages 234 and 235 

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