Bonjour je bloque sur c'est exercice aides MOI svp

Bonsoir,
A=24/18×5-1/2×20/3
=12/9×5-20/6
=60/9-20/6
=20/3-10/3
=10/3
B=7-1/15×5
=105/15-1/15×5
=104/15×5
=520/15
C=3/21×(13/5-18/15)
=3/21×(13/5-6/5)
=3/21×7/5
=21/105

bonsoir


A = 24/18 * 5 - 1/2 * 20 /3 
A =  8/6 * 5 - 1/2 * 20/3
A = 40/6 - 20/6  = 20/6 = 10/3 

B = 7 - 1/15 * 5 
B = 7 - 5/15
B = 7 - 1/3
B  = 21/3 - 1/3 = 20/3

C = 3/21 * ( 13/5 - 18/15 * 3/2)
C = 3/21 * ( 13/5 - 54/30)
C  = 1/7 * ( 78/30 - 54/30)
C = 1/7 * 24/30
C = 1/7 * 12/15 
c =  12/105 = 4/35