Sagot :

Bonjour,

13/13 = 1
1- 13/15 +5/9 +8/10 +3/7

-13/15 +8/10

= -130/150 + 120/150=  -10/150 = -1/15

1 - 1/15 +5/9 + 3/7

5/9 + 3/7 =  35/63 + 27/63 = 62/63

1- 1/15 +62/63

= 945/945 - 63/945 + 930/945

=  1812/945

= 604/315