Bonjour
1)
A = 7/8 x 3/4
A = 21/24
A = (3 x 7) / (3 x 8)
A = 7/8
B = 4/3 x 7/5
B = 21/15
B = (3 x 7) / (3 x 5)
B = 7/5
C = 1/5 x 8/7
C = 8/35
D = 5 x 72
D = 35/2
E = 3/8 x 5
E = 15/40
E = (5 x 3) / (5 x 8)
E = 3/8
F = 0,7/3 x 1/4
F = 0,7/12
F = (0,7 x 10) / (12 x 10)
F = 7/120
2)
a. 17/3 x 4/17
= 68/21
b. 7/11 x 11/7
= 77/77
= 1
c. 45/14 x 42/75
= 1890/1050
= (210 x 9) / (210 x 5)
= 9/5
d. 27/26 x 65/72
= 1755/1872
= (117 x 15) / (117 x 16)
= 15/16
e. 2 x 5/8
= 10/8
= (2 x 5) / (2 x 4)
= 5/4
f. 5,1/4 x 8
= 40,8/4
= (40,8 x 10) / (4 x 10)
= 408/40
= (8 x 51) / (8 x 5)
= 51/5.
