Je suis vraiment bloqué merci de m'aider

A = 1 / 2 + 1 / 4
= 2 / 4 + 1 / 4
= 3 / 4

B = 1 / 2 + 5 / 6
= 3 / 6 + 5 / 6
= 8 / 6
= 4 / 3

C = 1 / 2 + 3 / 10
= 5 / 10 + 3 / 10
= 8 / 10
= 4 / 5

D = 2 / 3 + 1 / 6
= 4 / 6 + 1 / 6
= 5 / 6

E = 5 / 4 + 7 / 2
= 5 / 4 + 14 / 4
= 19 / 4

F = 7 / 12 + 5 / 3
= 7 / 12 + 20 / 12
= 27 / 12


A = 2 / 10 + 65 / 100 + 4 / 10
= 20 / 100 + 65 / 100 + 40 / 100
= 60 / 100 + 65 / 100
= 125 / 100
= 5 / 4

B = 5 / 2 + 11 / 18 + 5 / 3
= 45 / 18 + 11 / 18 + 45 / 18
= 90 / 18 + 11 / 18
= 101 / 18