I faut mettre a ces fractions 100 au dénominateur : 44/80 ; 21/150 ; 38/200 ;27/225 !! Merci ( :

[A] 44/80 = 55/100 : (100 ÷ 80) × 44 = 1,25 × 44 = 55. [B] 21/150 = 14/100 : (100 ÷ 150) × 21 = 2/3 × 21 = 14. [C] 38/200 = 19/100 : (100 ÷ 200) × 38 = 0,5 × 38 = 19. [D] 27/225 = 12/100 : (100 ÷ 225) × 27 = 4/9 × 27 = 12. De rien ^^

100/80 = 5/4 = 1.25
donc (44*1.25 )  / (80 * 1.25) = 55/100

100/150 = 2/3
donc (21*2/3) / (150* 2/3) = 14/100

100 / 200 = 1.2 = 0.5
donc (38*0.5) / (200*0.5) = 19/100

100/225 = 4/9
donc (27*4/9) / (225*4/9) = 12/100