n°54 svp c pour demain

a) 24/40 = 8 x 3 / 8 x 5 = 3/5

b) 30/35 = 5 x 6 / 5 x 7 = 6/7

c) 18/63 = 9 x 2 / 9 x 7 = 2/7

d) 70/140 = 70 x 1 / 70 x 2 = 1/2

e) 100/175 = 25 x 4 / 25 x 7 = 4/7