Sagot :
Hello,
6/7 - 4/7 : 2/5
6/7 - 4/7 * 5/2
6/7 - 20/14 = 12/14 - 20/14 = -8/14 = -4/7
2/3 - 3/2 : 9/4 + 1/2 = 2/3 - 3/2 * 4/9 + 1/2 = 2/3 - 12/18 + 1/2 = 12/18 - 12/18 + 1/2 = 0 + 1/2 = 1/2
(3/7 - 1/5) : 16/21 = (15/35 - 7/35) : 16/21 = 8/35 * 21/16 = 168/560 = 21/70 = (7 * 3)/(7 * 10) = 3/10
Réponse :
Explications étape par étape
Bonjour,
A=6 sur 7 - 4 sur 7 ÷ 2 sur 5
A = 6/7 - 4/7 : 2/5
A = 6/7 - 4/7 x 5/2
A = 6/7 - 4/2 x 5/7
A = 6/7 - 2 x 5/7
A = 6/7 - 10/7
A = -4/7
B= 2 sur 3 - 3 sur 2 ÷ 9 sur 4 + 1 sur 2
B = 2/3 - 3/2 : 9/4 + 1/2
B = 2/3 - 3/2 x 4/9 + 1/2
B = 2/3 - 4/2 x 3/9 + 1/2
B = 2/3 - 2 x 1/3 + 1/2
B = 2/3 - 2/3 + 1/2
B = 1/2
C= ( 3 sur 7 - 1 sur 5 ) ÷ 16 sur 21
C = (3/7 - 1/5) x 21/16
C = [(3 x 5)/(7 x 5) - (1 x 7)/(5 x 7)] x 21/16
C = (15/35 - 7/35) x 21/16
C = 8/35 x 21/16
C = 21/35 x 8/16
C = (7 x 3)/(7 x 5) x 1/2
C = 3/5 x 1/2
C = 3/10