Bonjour
Calculer en simplifiant si possible et vérifier avec la calculatrice
A=2/7 - 3/7 × 14/9
A = 2/7 - 42/63
A = (2 x 9) / (7 x 9) - 42/63
A= 18/63 - 42/63
A= - 24/63
A = (3 x - 8) / (3 x 21)
A = - 8/21
B=-7/8 ×(2/3 - 1)
B = 7/8 x [2/3 - (1 x 3) / (1 x 3)]
B = 7/8 x (2/3 - 3/3)
B = 7/8 x (- 1/3)
B = - 7/24
C=4/5 × 1/4 + 2/5
C = 4/20 + 2/5
C = (4 x 1) / (4 x 5) + 2/5
C = 1/5 + 2/5
C = 3/5.
