Bonjour
A = 1*5 /2*5 -2*2/5*2
= 5/10 -4/10
= 1/10
B = 2*4/3*4 + 5/12
= 8/12 + 5/12
= 13/12
C = 2*7 / 2*3 = 7/3
D = 2/3*3. x 3 = 2/3
É = 7/4 x 3/2 = 7*3 / 4*2 = 21/8
F = 2/7 + 3*5/ 2*4
F = 2/7 + 15/8
F = 2*8/7*8 + 15*7 /8*7
F = 16/56 + 105/56
F =121/56