Bonjour,
E = 3/25 - 4/15
E = (3 x 3) / (25 x 3) - (4 x 5) / (15 x 5)
E = 9/75 - 20/75
E = - 19/75
F = - 3/4 + 5/16
F = (- 3 x 4) / (4 x 4) + 5/16
F = - 12/16 + 5/16
F = - 7/16
P = 2/3 x 9/26
P = 18/78
P = (6 x 3) / (6 x 13)
P = 3/13
Q = 3/5 : 7/10
Q = 3/5 x 10/7
Q = 30/35
Q = (5 x 6) / (5 x 7)
Q = 6/7.