bonjour pouvez vous m aidez m erci 1)210/420 ; 2) 1/8+3/24; 3) 1/3+1/6; 4) (1+2/3)x3/10; 5)14/3-16/3x1/2; 6)5/7+6/2x3/7; 7) (1+1/7)x7/32; 8)1-3/4x2/3; 9)6/4x(1

1) 210/420 = 210÷210/420÷210 = 1/2 = 0,5 ; 2) 1/8 + 3/24 = 1×3/8×3 + 3/24 = 3/24 + 3/24 = 6/24 = 6÷6/24÷6 = 1/4 = 0,25 ; 3) 1/3 + 1/6 = 1×2/3×2 + 1/6 = 2/6 + 1/6 = 3/6 = 3÷3/6÷3 = 1/2 = 0,5 ; 4) (1 + 2/3) × 3/10 = (3/3 + 2/3) ×3/10 = 5/3 × 3/10 = 5×3/3×10 = 15/30 = 15÷15/30÷15 = 1/2 = 0,5 ; 5) 14/3 - 16/3 × 1/2 = 14/3 - 16×1/3×2 = 14/3 - 16/6 = 14×2/3×2 - 16/6 = 28/6 - 16/6 = 12/6 = 12÷6/6÷6 = 2/1 = 2 ; 6) 5/7 + 6/2 × 3/7 = 5/7 + 6×3/2×7 = 5/7 + 18/14 = 5×2/7×2 + 18/14 = 10/14 + 18/14 = 28/14 = 28÷7/14÷7 = 4/2 = 4÷2/2÷2 = 2/1 = 2 ; 7) (1 + 1/7) × 7/32 = (7/7 + 1/7) × 7/32 = 8/7 × 7/32 = 8×7/7×32 = 56/224 = 56÷56/224÷56 = 1/4 = 0,25 ; 8) 1 - 3/4 × 2/3 = 1 - 3×2/4×3 = 1 - 6/12 = 12/12 - 6/12 = 6/12 = 6÷6/12÷6 = 1/2 = 0,5 ; 9) 6/4 × (1/3 + 1) = 6/4 × (1/3 + 3/3) = 6/4 × 4/3 = 6×4/4×3 = 24/12 = 24÷12/12÷12 = 2/1 = 2 ; 10) 5/7 + 9/7 = 14/7 = 14÷7/7÷7 = 2/1 = 2 ; 11) 1 - 3/14 × 7/2 = 1 - 3×7/14×2 = 1 - 21/28 = 28/28 - 21/28 = 7/28 = 7÷7/28÷7 = 1/4 = 0,25 J'espère t'avoir aider et que tu comprennes ce que j'ai fait.