Sagot :

CaMa

Réponse :

  1. 3/6 - 7/15 = 3/2*3 - 7/3*5 = 3*5/2*3*5 - 7*2/3*5*2 = 15/30 - 14/30 = 1/30
  2. 8/7 + 3/5 = 8*5/7*5 + 3*7/5*7 = 40/35 + 21/35 = 61/35
  3. 1/2 + 4/5 = 1*5/2*5 + 4*2/5*2 = 5/10 + 8/10 = 13/10
  4. 7/28 - 6/21 = 7/4*7 - 6/3*7 = 7*3/4*7*3 - 6*4/3*7*4 = 21/84 - 24/84 = -3/84 = -1/28

telephone16

Réponse :

Bonjour

Explications étape par étape

Réductions des fractions suivantes :

D =3/6 - 7/15

D = 3/6 X 15/15 -7/15 X 6/6

D = 45/90 - 42/90

D = 3/90 = 1/30

F = 8/7 + 3/5

F = 8/7 X 5/5 + 3/5 X 7/7

F = 40/35 + 21/35

F = 61/35

G = 1/2 + 4/5

G = 1/2 X 5/5 + 4/5 X 2/2

G = 5/10 + 8/10

G = 13/10

H = 7/28 - 6/21

H = 7/28 X 21/21 - 6/21 X 28/28

H = 147/588 - 168/ 588

H = -21/588

H = - 7/196

H = - 1/28