Bonjour,
1)
a. 4/5 + 3/5 x 1/2
= 4/5 + 3/10
= (4 x 2) / (5 x 2) + 3/10
= 8/10 + 3/10
= 11/10
b. - 3/4 x (1/5 - 3/10)
= - 3/4 x [(1 x 2) / (5 x 2) - 3/10]
= - 3/4 x (2/10 - 3/10)
= - 3/4 x - 1/10
= 3/40
c. 2/3 - 1/5 : 5/8
= 2/3 - 1/5 x 8/5
= 2/3 - 8/25
= (2 x 25) / (3 x 25) - (8 x 3) / (25 x 3)
= 50/75 - 24/75
= 26/75
2)
a. 11/10 = (11 x 300) / (10 x 300) = 3 300/3 000
b. 3/40 = (3 x 75) / (40 x 75) = 225/3 000
c. 26/75 = (26 x 40) / (75 x 40) = 1 040/3 000
11/10 > 26/75 > 3/4.
Le calcul qui donne le plus grand résultat est a.
