Question

calculați: d) 5/9×3/4 e)7/15×5/14 f)5/6×3/20​

Answer 1

Răspuns:

5 / 9 x 3 / 4 = 5 / 12

7 / 15 x 5 / 14 = 1 / 6

5 / 6 x 3 / 20 = 1 / 8

Explicație pas cu pas:

5 / 9 x 3 / 4

9 = 3 x 3

5 / ( 3 x 3 ) x 3 / 4

= ( 5 x 3 ) / ( 3 x 3 x 4 )

= 5 / ( 3 x 4 )

= 5 / 12

7 / 15 x 5 / 14

14 = 2 x 7

15 = 3 x 5

7 / ( 3 x 5 ) x 5 / ( 2 x 7 )

= ( 7 x 5 ) / ( 3 x 5 x 2 x 7 )

= 1 / ( 3 x 2 )

= 1 / 6

5 / 6 x 3 / 20

6 = 2 x 3

20 = 5 x 2 x 2

5 / ( 2 x 3 ) x 3 / ( 5 x 2 x 2 )

= ( 5 x 3 ) / ( 2 x 3 x 5 x 2 x 2 )

= 1 / ( 2 x 2 x 2 )

= 1 / 8