Bonjour,
3/4 + 1/2 =
3/4 + 2/4 = 6/4 = 3/2
1/12 de 42
(1*42) /12 = 42/12 = 21/6 = 7/2
3/5 * 1/6 = (3*1) /(5*6) = 3/30 = 1/10
2/5 + 3/20 =
8/20 +3/20 = 11/20
2-7/11=
22/11 -7/11 =15/11
3/10 -1/4 =
12/40 -10/40 = 2/40 = 1/20
260/715 = 52/143
(on divise par 5)
9/11* 2/3 = 18/33 = 6/11