27.5  Rekenregels voor wortels 2 >
1
2
a

1 3 = 1 3 3 en ook 1 2 = 1 2 2

b

1 3 = 3 9 = 1 9 3 = 1 3 3

1s
2s

Ze zijn elkaars omgekeerde, want 1 n n = 1 n n = 1 = 1 .

3
a

2 7 = 14 49 = 1 49 14 = 1 7 14

30 10 = 30 100 = 1 100 30 = 1 10 30

1 8 = 2 16 = 1 16 2 = 1 4 2

b

1 2 = 2 4 = 1 4 2 = 1 2 2
4 1 2 = 18 4 = 1 4 18 = 1 2 9 2 = 3 2 2
12 1 2 = 50 4 = 1 4 50 = 1 2 25 2 = 5 2 2 en
24 1 2 = 98 4 = 1 4 98 = 1 2 49 2 = 7 2 2 , dus
1 2 2 + 3 2 2 + 5 2 2 + 7 2 2 = 16 2 2 = 8 2 .

4
5
a

3 + 2 3 = 3 3

36 = 6

5 2 + 2 2 2 = 9 2

10 4 = 40

2 5 + 4 5 = 6 5

1600 = 40

kan niet eenvoudiger

20 = 4 5 = 2 5

b

6 + 6 9 = 6 + 1 3 6 = 1 1 3 6

6 9 + 24 9 = 1 3 6 + 1 3 24 = 1 3 6 + 2 3 6 = 6

c

12 12 = 12

1 = 1

4s
5s
a

2 2 3 = 4 2 3 = 4 2 3 = 8 3 = 2 2 3

b

3 3 8 = 9 3 8 = 9 3 8 = 27 8 = 3 3 8

c

5 1 5 + 1 = ( 5 1 ) ( 5 + 1 ) = 5 1 = 4 = 2

6

2 ; 4 ; 2

7

16 = 4

64 = 8

100 = 10

1 10.000 = 1 100

8
a

10 10

100 2 : 5 = 40 = 4 10 = 2 10

10 2 = 20

10

100

2

b

8 6

2 3 + 2 3 = 4 3

2 6

2 3 2 3 = 0

15 6 = 90

2 3 2 3 = 4 3 = 12

5 3 = 1 2 3

2 3 : 2 3 = 1

c

3 5 + 2 5 = 5 5

3 11 + 2 11 = 5 11

5

3 11 2 11 = 11

3 100 = 3 10 = 30

3 11 2 11 = 6 11 = 66

3 5 : 2 5 = 3 2 = 1 1 2

3 11 : 2 11 = 3 2 = 1 1 2

9

3

1 2 = 1 2 2

7

4 = 2

1 4 = 1 2

1 2 = 1 2 2

10
11

Linkerkolom:
1 2 2 + 2 2 = 2 1 2 2
6 9 + 2 6 = 1 3 6 + 2 6 = 2 1 3 6
2 14 + 14 49 = 2 14 + 1 7 14 = 2 1 7 14

Rechterkolom:
6 10 = 60 100 = 1 10 60 = 1 5 15
36 = 6
0,8 0,6 = 0,2

10s
11s

Linkerkolom:
2 6 3 4 = 2 3 3 2 = 8 9 = 72
2 4 3 5 = 2 2 3 2 3 = 4 9 3 = 36 3
2 4 3 5 5 3 = 2 2 3 2 3 5 5 = 180 15

Rechterkolom:
2 5 3 5 = 2 2 2 3 2 3 = 36 6
2 6 3 5 = 2 3 3 2 3 = 8 9 3 = 72 3
2 5 3 4 = 2 2 2 3 2 = 4 9 2

12