Réponse :
Explications étape par étape
Bonjour
-12/7 + 3/7 = (-12 + 3)/7 = -9/7
11/9 - 5/9 = (11 - 5)/9 = 6/9 = (2 x 3)/(3 x 3) = 2/3
19/12 - (-7/12) - 5/12 = 19/12 + 7/12 - 5/12 = (19 + 7 - 5)/12 = 21/12 = (3 x 7)/(3 x 4) = 7/4
A = -7/8 + 1/6
A = (-7 x 3)/(8 x 3) + (1 x 4)/(6 x 4)
A = -21/24 + 4/24
A = -17/24
B = 2 + 3/4
B = (2 x 4)/(1 x 4) + 3/4
B = 8/4 + 3/4
B = 11/4
C = 9/10 - 1/4 + 8/5
C = (9 x 2)/(10 x 2) - (1 x 5)/(4 x 5) + (8 x 4)/(5 x 4)
C = 18/20 - 5/20 + 32/20
C = (18 + 32 - 5)/20
C = 45/20
C = (9 x 5)/(4 x 5)
C = 9/4