Calculer , Puis mettre le résultat sous la ofrme d'une fraction Simplifiée : A= 12/25 / -8/15 = B= 11/5 - 9/5 * 7/18

A = 12/25 / -8/15
A = 12x15/-8x25
A = 4x3x3x5/-4x2x5x5
A = -9/10

B = 11/5 - 9/5*7/18
B = 11/5 - 9x7/5x18
B = 11/5 -9x7/5x2x9
B = 11/5-7/10
B = 11x2/5x2-7/10
B = 22/10-7/10
B = 15/10
B = 3x5/2x5
B = 3/2

A= 12/25 / -8/15
= 12/25 : -8/15
= 12/25 x (-15/8)
= -3 x 4 x 5 x 3 / 5 x 5 x 4 x 2
= -9/10

B= 11/5 -9/5 x 7/18
  = 11/5 -3 x 3 x 7 / 5 x 6 x 3
  = 11/5 -21/30
  = 11 x 6 / 5 x 6  -21/30
  = 66/30  -21/30
  = 45/30
  = 5 x 9 / 5 x 6
  = 9/6
  = 3 x 3 / 3 x 2
  = 3/2