calculer et écrire sous forme de fraction irréductibles.

F = 3 - 5 x 1/10 + 4 x 1/100
F = 3 - 5/10 + 4/100
F = 3 x 100 / 1 x 100 - 5 x 10 / 10 x 10 + 4/100
F = 300/100 - 50/100 + 4/100
F = 254/100
F = 2 x 127 / 2 x 50
F = 127/50

H = 18/23 + 3/4 - 2
                    5 + 3/4
H = 18/23 + 3/4 - 2 x 4 / 1 x 4
                   5 x 4 / 1 x 4 + 3/4
H = 18/23 + 3/4 - 8/4
                   20/4 + 3/4
H = 18/23 - 5/4 : 23/4
H = 1/23 - 5/4 x 4/23
H = 1/23 - 20/92
H = 1 x 4 / 23 x 4 - 20/92
H = 4/92 - 20/92
H = - 16/92
H = 4 x - 4 / 4 x 23
H = - 4/23

I = 2 +      1___
          3 + 1/16
I = 2 +               2________
         3 x 16 / 1 x 16 + 1/16
I = 2 +       2______
         48/16 + 1/16
I = 2 + 2 : 49/16
I = 2 + 2 x 16/49
I = 2 + 32/49
I = 2 x 49 / 1 x 49 + 32/49
I = 98/49 + 32/49
I = 130/49