Réponses

2014-01-13T22:00:33+01:00
1) 1/5 + 2/5 x 4/3
= 3/5 x 4/3
= 12/15
= 4/5

2) 13/12 - 3/12 x 1/3
= 10/12 x 1/3
= 10/26
= 5/13

3) 5/7 x (3/5 + 1/10)
= 5/7 x (6/10 + 1/10)
= 5/7 x 7/10
= 35/70
= 5/10
= 1/2

4) 21/20 x (9/14 - 2/7)
= 21/20 x (9/14 - 4/14)
= 21/20 x 5/14
= 105/280
= 21/56
Poue le 1) tu t'ai tromper priorité de calculs :)
2014-01-13T23:05:46+01:00
A=1+2x4
     5  5x3
A= 1+8
     15
A= 9
    15
2) 13/12 - 3/12 x 1/3
      13/12-3/36
       10/36