Réponses

2014-09-23T20:26:08+02:00
Bonsoir

A = -9/7 x ( -27/33 - 77/33)
A = -9/7 x - 104/33
A =  936/231 = 312/77

B = 5 - (-1/4) = 20/4 + 1/4 = 21/4 
2014-09-23T20:54:46+02:00
A=-9/7×(-9/11+(-7)/3)=(-9/7)x(-9/11)+(-9/7)×(-7/3)=(9×9)/(7×11)+(9×7)/(7x3)
A=9/3+81/77=(77×9+3x81)/(3x77)=936/231=(312×3)/(77×3)=312/77

B=5-((-1)/4)×1=5+1/4=(5×4+1)/4=21/4

C=(2/9+3)/(10/3+5)=((3+3×9)/9)/((10+5×3)/3)=(30/9)/(25/3)=(10/3)/(25/3)
C=(10/3)×(3/25)=10/25=2/5