a) 45/36 = (9*5) / (9*4) = 5/4
b) 124/128 = (4*31) / (4*32) = 31/32
c) 105/500 = (5 * 21) / (5*100) = 21/100
d) 180/360 = (1*180) / (2*180) = 1/2
Bjr
b) 124/128 =
(22 × 31)/27 =
((22 × 31) : 22) / (27 : 22) =
31/25 =
31/32
31/32 =
31 : 32 =
0,96875 ≈
0,97
C) 105/500 =
(3 × 5 × 7)/(22 × 53) =
((3 × 5 × 7) : 5) / ((22 × 53) : 5) =
(3 × 7)/(22 × 52) =
21/100
21/100 =
21 : 100 =
0,21
a) 45/36 =
(32 × 5)/(22 × 32) =
((32 × 5) : 32) / ((22 × 32) : 32) =
5/22 =
5/4
5 : 4 = 1 et reste = 1 =>
5 = 1 × 4 + 1 =>
5/4 =
(1 × 4 + 1) / 4 =
1 + 1/4 =
1 1/4
1 1/4 =
1 + 1/4 =
1 + 1 : 4 =
1,25
d) 180/360 =
(22 × 32 × 5)/(23 × 32 × 5) =
((22 × 32 × 5) : (22 × 32 × 5)) / ((23 × 32 × 5) : (22 × 32 × 5)) =
1/2
1/2 =
1 : 2 =
0,5
