Question

z 1 oblicz

a) 4/9 + 1/2 =

b) 7/15 + 2/3 =

c) 5/8 + 1/6 =

d) 2 1/9 + 2 5/6 =

z 2 oblicz

a) 9/13 - 1/2 =

b) 9/16 - 3/8 =

c) 7/10 - 4/15 =

d) 2 1/8 - 1 5/12

z 3 oblicz

a) 3/19 * 5 =

b) 1 5/12 * 6 =

c) 7/11 : 3 =

d) 1 1/9 : 20 =

Answer 1

zad 1.

 

a)

 

4/9 + 1/2 =

 

= 8/18 + 9/18=

 

= 17/18

 

 

 

b)

 

7/15 + 2/3 =

 

= 7/15 + 10/15=

 

= 17/15=

 

= 1 i 2/15

 

 

 

 

c)

 

5/8 + 1/6 =

 

= 15/24 + 4/24=

 

= 19/24

 

 

 

 

d)

 

2  i 1/9 + 2  i 5/6 =

 

= 2 i 2/18 + 2 i 15/18 =

 

= 4 i 17/18

 

 

 

 

zad 2

a)

 

9/13 - 1/2 =

 

= 18/26 - 13/26=

 

= 5/26

 

 

 

b)

 

9/16 - 3/8 =

 

= 9/16 - 6/16 =

 

= 3/16

 

 

 

 

c)

 

7/10 - 4/15 =

 

= 21/30 - 8/30=

 

= 13/30

 

 

 

 

d)

 

2 i 1/8 - 1 i  5/12=

 

= 2 i 3/24 - 1 i 10/24=

 

= 1 i 27/24 - 1 i 10/24=

 

= 17/24

 

 

 

 

zad 3.

a)

 

3/19 * 5 = 15/19

 

 

b)

 

1  5/12 * 6 =

 

= 17/12 * 6=  (skracam 12 z 6)

 

= 17/2 * 1=

 

= 17/2=

 

= 8 i 1/2

 

 

 

 

c)

 

7/11 : 3 =

 

= 7/11 * 1/3=

 

= 7/33

 

 

 

 

d)

 

1 i 1/9 : 20 =

 

= 10/9 * 1/20=  (skracam 10 z 20)

 

= 1/9 * 1/2=

 

= 1/18