Réponse :
Explications étape par étape :
A=5/4+10/4 × 9/8
A = 5/4 + ( 2× 5 ×9) /(2×2×8)
A = 5/4 + 45/16
A = ( 5 × 4 ) / (4 × 4) + 45/ 16
A = 20 / 16 + 45 / 16 = 65 / 16
B=(2 / 3 + 1 / 5) / (11 / 4 - 3 / 5 )
B = ((2×5)/(3×5) + (1×3)/(3×5)) / (11×5)/(4×5) - (3×4)/(5×4))
B = ((10 + 3) / 15) / ( (55 - 12) / 20)
B= (13/15) / (43/20)
B = (13 / 15) × (20/ 43)
B = (13 × 4 × 5) / (3 × 5 × 43)
B = (13×4) / (3×43)
B = 52 / 129
C= - 8 - 2×3 / 7 - 11
C = - 8 - 6/ 7 - 11
C = - 19 - 6/7 = - 133/7 - 6/7
C = - 139 / 7
