bonjour
a)
9/11 - 5/33 = dénominateur commun 33
( 9 x 3)/(11 x 3) - 5/33 =
27/33 - 5/33 =
(27 - 5)/33 =
22/33 = on simplifie par 11
2/3
b)
25/42 + 5/6 = dénominateur commun 42
25/42 + (5 x 7)/(6 x 7) =
25/42 + 35/42 =
(25 + 35/42 =
60/42 = on simplifie par 6
10/7
