Réponse:

H= 4/3 + 5/2 x 7/15

H= 4/3 + (5x7/2x15)

H= 4/3 + 35/30

H= 4x10/3x10 + 35/30

H= 40/30 + 35/30

H=75/30 = 5/2

I= -7/4 x (1x2/5x2 - 3/10)

I= -7/4 x (2/10 - 3/10)

I= -7/4 x 1/10

I= -7x1 /4x10

I= -7/40

J= 8/3 + 5 : (1x5/1x5 - 2/5)

J= - - - - - - -(5/5 - 2/5)

J= 8/3 + 5 : 3/5

J= 8/3 + 5x5/5x3

J= 8/3 + 25/15

J= 8x5/3x5 + 25/15

J= 40/15 + 25/15

J= 65/15 = 13/3

K= 1x2/1x2 + 1/2 : 1x3/4x3 - 3x4/3x4

K= 2/2 + 1/2 : 3/12 - 12/12

K= 3/2 : 9/12

K= 3x12 / 2x9

K= 36/18 = 2

J'espère t'avoir aidé !