Réponses

2014-02-16T15:07:06+01:00


148: a) 3/5 + 7/5 = 10/5

b) 1/2 + 5/6 = 3/6 + 5/6 = 8/6 = 4/3

c) 3/2 * 9/10 = 27/20

d) 32/81 * 5/8 = 160/648 = 20/81

149): a) 3/7 * 22/8 = 66/56 = 33/28
b) 18/9 * 5/4 = 90/36 = 5/2
c) 8/8 * 15/12 = 120/96 = 5/4
2014-02-16T15:16:28+01:00
A = 3/4 *4/5 + 7/5 =12/20 +7/5 =12/20 +28/20 =40/20 = 2
B  =1/2 + 5/2 * 1/3 = 1/2 +5/6 = 3/6 +5/6 = 9/6 =3/2
C = 3/2 (3/5+5/10) = 3/2 (6/10+5/10) = 3/2  x11/10 = 33/20
D = (7/9-31/81) x 5/8 = (63/81 -31/81) x 5/8 = 32/81 x 5/8 =8*4/81 x 5/8 = 20/81

A = 3/7 x 13/8 +9/8 = 39/56 +9/8 = 39/56 + 63/56 = 102/56= 51/28
b = 11/9 +7/9 x 5/4 = 11/9 +35/36 =44/36+35/36=79/36
c = (10/8-1/4) x (7/12 +2/3) = (10/8 -2/8) x (7/12 +8/12) = (8/8) x (15/12) = 1x 15/12 = 15/12