Bonjour,
Calculer:
C= (5/7-2/3) (1/5-9/2)
C= [(5x3-2x7)/ (7x3)] / [(1x2-9x5)/ (5x2) ]
C= (15-14)/21)(2-45)/10)
C= (1/21)(-43/10)
C= (1x-43)/(21x10)
C= -43/210