Réponses

2014-01-11T19:07:02+01:00
1) A= 2÷9 + 4÷3 × 1÷6 + 5÷3
    A=2÷9 + 4×3÷3×3 × 1÷6 + 5×2 ÷ 3×2
    A=2÷9 +12÷9×1÷6+10÷6
    A=14÷9×11÷6
    A=2×7×11÷3×3×3×2 (tu barres les deux 2 pour simplifier)
    A=77÷27 

Pour les autres je sais pas mais c'est le meme systeme . 

4) I=4÷5×2÷3×2÷15×2÷3                                   La J c le meme systeme
    I=2÷3(4÷5+2÷15)
    I=2÷3(4×3÷5×3+2÷15)
    I=2÷3(12÷15+2÷15)
    I=2÷3+14÷15
    I=28 ÷45
2014-01-11T20:21:28+01:00
* Représente le signe de la multiplication
/ le signe de la division
Exo 1
A = 2/9 + 4/3*1/6 + 5/3
A = 2/9 + 4/18 + 5/3
A = 4/18 + 4/18 + 30/18
A = 38/18
A = 19/9
B = (2/9+4/3) * (1/6 + 5/3)
B = (2/9+12/9) * (1/6 + 10/6)
B = (14/9) * (11/6)
B = 14*11 / 9*6
B = 154/54
B = 77/27
C = 1- (9/7 - (5/6*3/7))
C = 1- (9/7 - (15/42))
C = 1- (9/7 - 15/42)
C = 1 -(54/42 - 15/42)
C = 1 -(39/42)
C = 42/42 - 39/42
C = 3/42
C = 1/14
D = 3/2 -(3/2*1/5) + (24 * 1/30)
D = 3/2 - (3/10) + 24/30
D = 3/2 -3/10 + 24/30
D = 45/30 - 9/30 + 24/30
D = 60/30 
D = 2
Exo 2
E = 3/7 * ( 5x/2 + 1/4)
E = 15x/14 + 3/28
E = 30x/28 + 3/28
E = (30x+3)/28
F = (2a/3 - 3/2) * 5/2
F = 10a/6 - 15/4
F = 20a/12 - 45/12
F = (20a-45) / 12
Exo 3
G = 4/5 + (3/2 * 7/5)
G = 8/10 + 21/10
G = 29/10
H = 18 * (1/4+1/8)
H = 18 * (2/8+1/8)
H = 18 * 3/8
H = 54 / 8
H = 27/4
Exo 4
I = 4/5 * 2/3 + 2/15 * 2/3
I = 2/3 * ( 4/5 + 2/15)
I = 2/3 * (12/15 + 2/15)
I = 2/3 * 14/15
I = 28/45
J = 5/6 * 3/4 - 3/4*5/9
J = 3/4 * ( 5/6 - 5/9)
J = 3/4 * (15/18 - 10/18)
J = 3/4 * 5/18
J = 15/72