Réponse :
Explications étape par étape :
Bonjour
1)
A = 2/3 + 4/5 = 10/15 + 12/15 = 22/15
B = 3 + 5/3 = 3/1 + 5/3 = 9/3 + 5/3 = 14/3
C = 1/3 - 5/6 = 2/6 - 5/6 = -3/6 = - 1/2
D = - 2/3 + 3/2 = - 4/6 + 9/6 = 5/6
2)
E = 8/12 = (4×2) /(4×3) = 2/3
F = - 15 / (-6) = ( -3× 5) / (-3×2) = 5/2
G = 100/ (-40) = (20×5) / (20 × ( -2)) = 5/ (-2)
3)
H = 1/2 ×4/7 = (4×1) /(2×7) = (2 × 2 × 1) / (2 × 7) = 2/7
I = 15 × 13/3 = 3×5 ×13 / 3 = 5×13 = 65
J = 3/4 × 12/15× 5/7 = (3×12×5) / (4×15×7) = (3×3×4×5) /(4×3×5×7)= 3/7
4)
K = 2 - 1/3 × 4 - 1/5 = 2 - 4/3 -1/5 = 30/15 - 20/15 -3/15 = 7/15
L =(2 - 1/3) × 4 - 1/5 = (6/3 -1/3) × 4 - 1/5 = 5/6 × 4 - 1/5 = (5×2×2) /(2×3) - 1/5
L =10/3 - 1/5 = 50/15 -3/15 = 47/15
M = 2 - (3/2)² = 2 - 9/4 = 8/4 - 9/4 = - 1/4
N = 2 - 3²/2 = 2 - 9/2 = 4/2 - 9/2 = - 5 / 2
