Sagot :
Bonjour,
1/3 * 1/4 * 12 = 1/12 * 12 = 1
2/5 + 1/4 = 8/20 + 5/20 = 13/20
2/5 - 1/4 = 8/20 - 5/20 = 3/20
D = B/C = 13/20 * 20/3 = 260/60 = 26/6 = 13/3
Réponse :
Explications étape par étape
Bonsoir,
1. Le tiers du quart de 12 est égal à 1?
le quart de 12 : 12 x 1/4 = 3
le tiers du quart de 12 : 3 x 1/3 = 1
B = 2/5 + 1/4
B = (2 x 4)/(5 x 4) + (1 x 5)/(4 x 5)
B = 8/20 + 5/20
B = 13/20
C = 2/5 - 1/4
C = 8/20 - 5/20
C = 3/20
D = B/C
D = (13/20)/(3/20)
D = 13/20 x 20/3
D = 20/20 x 13/3
D = 13/3
E = 7/15 - 2/15 x 9/4
E = 7/15 - 9/15 x 2/4
E = 7/15 - (3 x 3)/(3 x 5) x 2/(2 x 2)
E = 7/15 - 3/5 x 1/2
E = 7/15 - 3/10
E = (7 x 2)/(15 x 2) - (3 x 3)/(3 x 10)
E = 14/30 - 9/30
E = 5/30
E = 1/6
F = 3/4 + 5/4 : (4/3 - 1/2)
F = 3/4 + 5/4 : (8/6 - 3/6)
F = 3/4 + 5/4 : (5/6)
F = 3/4 + 5/4 x 6/5
F = 3/4 + 5/5 x 6/4
F = 3/4 + 6/4
F = 9/4