Bonjour
J= -21/-16 - 25/-24
J = (21 x 3) / (16 x 3) + (25 x 2) / (24 x 2)
J = 63/48 + 50/48
J = 113/48
B= -4/5/2/10
B = - 4/5 x 10/2
B = - 40/10
B = (10 x - 4) / (10 x 1)
B = - 4
C = 15/28 × 7/25 × 1/6
C = 105/700 x 1/6
C = 700/4 200
C = (700 x 1) / (700 x 6)
C = 1/6
K= 21/-8 × -22/15
K = 462/120
K = (6 x 77) / (6 x 20)
K = 77/20.
