calculer et donner les réponses sous forme simplifiée
A = 1/3 -5/7
= 7/21 - 15/21
= - 8/21
B = -7* 5/21
= - 35/21 = - 7 /3
C = (3/7) ² = 9/49
D = - 8/5 : 4/3 = - 8/5 * 3/4 = - 24/20 = - 6 /5
E = 5/8 + 1/12 = 15/24 + 2 /24 = 17/24
Explications étape par étape:
Tu ne sais toujours pas calculer des fractions? ce n´est pas ton 1er exo pourtant!
A = (1×7)/(3×7) - (5×3)/(7×3)
A = 7/21 - 15/21 = -8/21
B = ( -7 × 5)/21 = (-7×5)/(3×7) = -5/3
C = 3/7 × 3/7 = (3×3)/(7×7) = 9/49
D = 8/5 × 3/4.= (2×4×3)/(5×4) = 6/5
E = (5×3)/(8×3) + (1×2)/(12×2) = 15/24 + 2/24 = 17/24
